Distributed fiber sensor for identifying foreign body intrusion and foreign body intrusion signal sensing processing method

Abstract

The invention discloses a distributed fiber sensor for identifying foreign body intrusion and a foreign body intrusion signal sensing processing method and belongs to the technical field of optics. According to technical key points, the method comprises the following steps: dividing incident light of a laser into two paths by virtue of an optical fiber coupler I, enabling one path of probe light to pass through an acoustic optical modulator, an erbium doped optical fiber amplifier I and a circulator I to enter to-be-detected optical fibers, generating backward scattered light, enabling the light to enter a filter via an erbium doped optical fiber amplifier II and a circulator II, enabling a reflection end of the filter to pass through the circulator II, enabling the light enter an opticalfiber coupler II together with reference light, outputting beat frequency light by the optical fiber coupler II, performing photoelectric conversion by adopting a balanced detector, acquiring signalsby a data acquisition unit, and transmitting the signals into an upper computer. According to the method disclosed by the invention, the intrusion mode is identified by adopting a support vector machine (SVM) based algorithm. The method comprises the steps: acquiring signals in different intrusion modes to perform feature extraction and classification, forming a training data sample set, and training by adopting the SVM based algorithm, thereby obtaining a subsequent identification network model. The method disclosed by the invention is used for sensing and identifying foreign body intrusion events.

Description

technical field [0001] The invention relates to a distributed optical fiber sensor and a signal perception processing method, in particular to a distributed optical fiber sensor for identifying foreign object intrusion and a foreign object intrusion signal perception processing method, belonging to the field of optical technology. Background technique [0002] The distributed optical fiber sensing system uses optical fiber as the sensing medium, and can perform real-time remote monitoring of targets within the length of the optical fiber. Φ-OTDR (phase-sensitive optical time-domain reflectometer) system can detect weaker vibration signals than traditional OTDR (optical time-domain reflectometer) systems in practical applications . [0003] From the development of Φ-OTDR technology for more than 20 years, with the continuous development of optical fiber devices and the continuous maturity of optical fiber technology, Φ-OTDR technology has gradually developed in the direction...

AI Technical Summary

Problems solved by technology

Under the interference of many factors, whether the different intrusion events of intruders can be accurately detected and distinguished is the main problem of whether the Φ-OTDR distributed optical fiber sensing system can be put into practical use

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