Research On All Fiber Regional Style Intelligent Perimeter Security Technique

Interferometric optical fiber sensing technology is highly sensitive to dynamic signal and every point in the optical fiber is capable of sensing.It has a great advantage in distributed measurement and long distance monitoring,which can be making it very applicable to the security monitoring.The existing fiber perimeter security systems have two major styles: positional system and regional system.The regional system is more suitable for some which does not require precise positioning of invasion.The implementation,the structure and cost of this style are relatively low,thus its market demand is larger.However,security system based on interferometric optical fiber sensing exists polarization induced fading,which can increase the failure rate.And the security system inevitably subjects to environmental interference which can increase false alarm rate.In this paper,optical fiber regional style perimeter security system is further studied and its performance is optimized and intelligent.In the meantime,the instrumentation of this system is realized.The main contents are described as follows:1.Through compared several kinds of interference fiber sensing technology,we constructed the optical path on the basis of Michelson interference sensing technology with FRMs.We analyzed the sensing principle of this system,especially the effect of FRMs in maintaining the stability of the output light signal.2 Since the environmental noise has serious impact on the system,we analyzed the characteristics of the intrusion signal and environment noise in time domain.Then we proposed a novel method of quick decision of invasion.In order to reduce the interference of the heavy rain on the system,the algorithm flow had been added a constraint condition which can improve its performance.3.On the overall design of the system,the system was divided into five modules.Modular system is conducive to the implementation of the instrument and the maintenance.The realization of each module and the connection relationship between each module were introduced in detail.We constructed the software based on Lab VIEW to realize man-machine interaction.The software included a main interface and three sub interfaces.The main interface was divided into seven modules.The realization of all the interfaces and modules are completed.4.The system had been tested,including the intrusion test and the resistance ability to wind and rain.We also tested the message alarm.The experiment results show that the failure is under 1% and the false alarm rate is under 5%.No matter which region was invaded,the alarm message sent by the system was correct.