Design And Realization Of Early Warning System Based On Optical Fiber Sensor

In recent years, along with the rapid development of highway, railway and other infrastructure, slope accidents happened on both sides of subgrade pose a serious threat to people's life and property safety.Therefore, it has great significance to solve the problems existed in the traditional slope safety monitoring technology by designing integrated,intelligent and automatic warning system to conduct a comprehensive monitoring to accidents prone areas so as to guarantee people's life and property safety.In order to reduce the danger of the slope accident in this area, the slope accident in Quanzhou of Fujian Province has brought great harm to the people, and relying on the cooperation project of slope early warning with the northwest institute of China Railway. This thesis adopts fiber optical sensor based on the principle of Optical Time-Domain Reflection(OTDR) as the core component and employs measured data as essential data sources. Through analyzing the feasibility of the system requirements,this thesis realizes the selection and design of system hardware measuring module and accomplishes the software control client of warning system on the basis of B/S structure, organically combines the hardware and software together. The slope accidents can achieve real-time and effective early warning through the process and analysis of measured data, thus, making the monitoring personnel to take corresponding safety measures in the first time, minimizing the accident loss.Firstly, the background and significance of the research are introduced.By introducing the development status of the fiber sensor and the slope monitoring technology, the feasibility and necessity of using fiber optical sensor for slope safety monitoring are fully explained.Then, the thesis introduces optical fiber, the principle of optical time domain reflection and the optical fiber sensor based on optical time domain reflection principle. On the basis of the above theory knowledge, the paper puts forward the overall design scheme of slope warning system and specifically illustrates the design structure of the system.Thirdly, according to the design scheme, the selection and the design of hardware modules of warning system are described in detail, using the LNMP components and Web three-layer development modes to complete the B/S software structure of the warning system.Finally, the thesis introduces the using methods, function and effect of the warning system; the actual monitoring results of early warning system are analyzed in the paper. Based on this, the thesis proposes and verifies the optimization solutions to improve the system Signal to Noise Ratio (SNR) based on C-S compound-coding techniques.