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Design Of Optical Fiber Vibration Early Warning System For Multiple Defense Areas

Posted on:2022-02-17Degree:MasterType:Thesis
Country:ChinaCandidate:P YanFull Text:PDF
GTID:2518306542983189Subject:Control Engineering
Abstract/Summary:PDF Full Text Request
Distributed optical fiber vibration sensing technology has become an emerging modern security method due to its unique advantages such as wide monitoring range,passive detection and freedom of deployment methods.It has been widely used in rail transit,oil and gas pipelines,perimeter security and other fields.Among them,the optical fiber vibration sensing system based on the principle of laser interference can accurately sense external vibration signals and meet the monitoring needs of intrusion events in the security area.However,the system still needs to be further improved in terms of monitoring range and real-time performance.In response to the above problems,this paper has design a multi-defense zone optical fiber vibration early warning system based on the principles of Michelson interference and Sagnac interference.The above-mentioned two types of interference structures are merged by the optical fiber splitter,thereby the number of defense zones for simultaneous monitoring is expanded and the monitoring range of the system is increased.Multi-channel signal acquisition and high-speed communication hardware circuits are designed to improve the real-time response performance of the optical fiber vibration early warning system.The research content of this article mainly includes the following aspects:(1)The theory of optical fiber vibration sensing based on laser forward interference is analyzed.Through the performance comparison of interference structure and the selection of system device parameters,a multi-defense zone optical fiber vibration early warning system based on the fusion structure of Michelson interference and Sagnac interference is built,which has improved the detection range of system.(2)Laser power supply circuit,photoelectric detection circuit,signal filter circuit and multi-channel acquisition circuit is designed.Then data transmission communication schemes such as USB communication and Ethernet communication is improved the real-time performance of vibration detection.(3)A visual human-computer interaction interface is designed using the MFC compilation environment,which has functions of multi-defense zone operation control,data display,data storage,alarm threshold setting,intrusion event recording,etc.Then the linkage of camera video surveillance is realized through application program interface calls.Finally,using the enterprise We Chat client to accomplish the push of We Chat warning information.(4)The integration of the engineering prototype of the multi-defense zone optical fiber vibration early warning system is finished through the mechanical structure design and circuit layout optimization.Then the performance indicators of the engineering prototype such as standard waveform detection,frequency response range,intrusion event miss rate,system power loss and system response time is tested and evaluated.The above research shows that the multi-defense zone optical fiber vibration early warning system can realize the real-time detection of different external intrusion events through multiple independent zones,and provides an optimization plan for the improvement of monitoring range and real-time performance for the perimeter security early warning of key places.
Keywords/Search Tags:Distributed optical fiber sensing, Multi-zone monitoring, Michelson interference, Sagnac interference, Hardware circuit design
PDF Full Text Request
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