Performance Analysis Of Intelligent Optical Fiber Fence Sensing System And Application Research Of Perimeter Alarm

This paper studies the technology of intelligent optical fiber fence perimeter protection system.Facing the major needs of the perimeter security protection of important places,fiber fences are installed along the perimeter to build a "tangible" protective net to form a closed security protection area.The integrated technology of physical blocking and intrusion detection technology is adopted,which not only plays a role in deterrence,but also realizes real-time online monitoring,which reflects the perimeter protection concept of "blocking first,alarming second".In this paper,the sensitivity,real-time,large-scale networking and false positivity of the Michelson and Sagnac interferometric optical fiber sensor system used in fiber fence are studied.The main research work is as follows:(1)The vibration sensing mechanism of common interferometric fiber optic interferometers is theoretically analyzed,and the sensing mechanisms,advantages and disadvantages of different interferometric fiber optic sensors are compared,and the Michelson and the MZ-Sagnac sensors’ unique advantages are proved.(2)The overall framework design of intelligent fiber optic fence sensor system is proposed,including fiber optic sensor module,data acquisition and processing module and alarm module,and the maximum number of defense zones,monitoring distance,sensor sensitivity,response time,false alarm failure rate and event identification performance of perimeter system are deeply discussed.The system networking scale is verified.It is proved that sensitizing the sensing fiber,optimizing the laying mode and adjusting the length of MZSagnac delay fiber can effectively improve the sensitivity.The frequency characteristic specific gravity algorithm proposed in this paper can better reflect the severity of abrupt change.(3)Michelson and MZ-Sagnac sensing systems were tested in the field,and the difference of the detection waveforms of the two systems was analyzed to verify that the detection of this system has certain real-time performance,high sensitivity,and can distinguish large movements.Experiments show that MZ-Sagnac performs better on false positives,and Michelson performs better on sensitivity,and false positives are correlated with wind and rain environments;After applying different disturbance actions to the two systems,by observing!the freq time domain waveform,it is verified that the Michelson system performs better in sensitivity,and the real-time response characteristics of the two systems are better,and both have good induction to large-scale actions.