Optical Fiber Sensing Key Technologies Research Based On Distributed And Limited Node Monitoring

Compared with traditional electrical measurements, as for its high sensitivity,immunity to electromagnetic interference, multi-physics parameters multiplexing anddistributed measurement, corrosion resistance and other advantages,optical fibersensing technology has achieved a major breakthrough and accessed to a wide rangeof applications in large composite and concrete structures, electrical, medical,chemical, and oil and gas industry and other fields. In recent years, fit the backgroundof Tianjin committed to the development of the Haihe River valley and the citybuilding renovation. New bridges, buildings and the old bridge reconstruction projectincreased. The paper designed to develop a set of distributed and limited nodemonitoring digital fiber-optic sensing signal demodulation system. It mainlycomposited by the two parts: the FFP-TF technology-based FBG optical fiber sensingsystem and OTDR distributed optical fiber detection system.Papers has researched around key areas such as the fiber Bragg grating coupledmode theory and the sensing mechanism, the theoretical basis of the OTDRdistributed sensing based on Rayleigh scattering, Raman scattering, Brillouinscattering, optical fiber sensing mechanism, the sensing signal demodulation systemand the sense signal processing. Focusing on the FFP-TF-based technology to buildthe FBG digitized sensor signal spectrum demodulation system and the design ofdistributed fiber optic sensing system based on OTDR technology. The main contentof the paper is as follows:(1) Derived the fiber grating coupled mode theory, numerical algorithms, andsensing demodulation system model, discusses the FBG sensing mechanism in thedetection field and based on the FFP-TF build the grating spectrum demodulationsystem solutions; Analysis the sensing mechanism from three different lightdispersion.(2) Completed the selection and interconnection of various hardware modules,realized the data acquisition module software algorithms for hardware architectureand design spectral peak searching, positioning algorithms and alarm displayalgorithm, as well as build interactive interface, complete the analysis and testing ofthe system performance. (3) The design of the hardware architecture of the system, the selection andinterconnection testing of system hardware module, and complete software module,performance analysis and OTDR event search algorithm. In addition, combine withthe FBG digitized spectrum demodulation system in labview.