Research On The Key Technologies Of Optical Fiber Fence Sensing Warning System

With the rapid development of optical communication technology, optical fiber sensing technology has brought new vigor and vitality to the field of safety protecting.The optical fiber fence sensing warning system based on optical fiber sensing technology draws more and more attention of the society. Comparing with the traditional fence alarm systems, optical fiber fence sensing warning system has a lot of advantages, such as high sensitivity, anti-electromagnetic interference,anti-corrosion, passive devices, large monitored region, etc. And it takes optical fiber as the sensing medium to monitor the unexpected invasion events in real-time and remote at the field of security monitoring. At present, monitoring technology based on optical fiber sensor has been applied in many fields, such as the monitoring of petroleum and natural gas pipeline, health inspection of bridges, buildings and other large structures and so on. The optical fiber fence sensing warning system not only has an important application prospects in the field of safety protecting, it may also become one of the main research in intelligence monitoring field. Therefore, the research of optical fiber fence sensing warning system has important practical value.In this thesis, a new type of optical fiber fence sensing warning system based on Mach-Zehnder(M-Z) interference technology is designed after comparing several detection technologies used in optical fiber fence systems. And the feasibility analysis of the system is performed as well. At last, the result demonstrates that the optical fiber fence sensing warning system based on M-Z interference technology can detect the intrusion actions effectively. The research is practical and the detailed work is shown as following:(1) The research status at home and abroad of optical fiber fence sensing warning system is analyzed and it can be drawn the conclusion that optical fiber fencesensing warning system based on M-Z interference technology has great value for scientific research.(2) Several detection technologies used in optical fiber fence system are analyzed and the M-Z interference technique is adopted to design the system.(3) A classification method of Support Vector Machines(SVM) based on binary tree is proposed to classify the intrusion actions and three algorithms of time delay estimation are discussed.(4) The optical fiber fence sensing warning system based on M-Z interference technology is designed, and the host of optical fiber fence system is designed to be a five-layer information model, and the feasibility analysis of the system is performed as well.(5) The optical fiber fence sensing warning system is tested in outdoor environment and the result shows that the system based on M-Z interference technology is effective for detecting intrusion actions.