The Research And The Design Of The Distributed FBG Measurement System

FBG sensor is one of the current focal research fields in the fiber sensor technique fields. It is widely applied in many fields such as the civil engineering structure, aviation and spaceflight, shipping, oil and chemistry industry, medicine, nucleus industry etc. Presently many imported instruments are applied to structural health diagnose in bridge and construction industry, but the key technique such as the demodulation method of the FBG sensor and the research of FBG sensor measurement system are still in the phase of exploration, digestion and absorption. These technique and research are a great distance away to realize independent R&D and practicality of engineering.For the purpose of development of FBG sensor system, a distributed FBG measurement system is investigated and designed in this paper. In the system, a fiber Fabry-Perot tunable filter is used to demodulate the wavelength change of the FBG sensors and a D/A transmission circuit controls the tunable signal . All the signals indicating the wavelength changes are inputted into a A/D sampling card. The computer software is designed to sample, filter and analysis the output signal of FBG.This paper discussed the feasibility of the system scheme and then developed the whole measurement system and the software. The main research works are as follows:1, The distributed FBG sensor system is discussed on theory and measurement method. The key technique of the system, especially the wavelength demodulation technique and the realization is studied. A demodulation system of FBG sensor is designed;2, The circuit modules of the photoelectric system are designed and the connection and the debugging of the whole system is completed;3, The application of embedded computer system in the distributed FBG measurement system and the realization method are investigated. The software of the system is designed by Delphi language and Access database which has the main functions such as sampling, data storage, display, modification, query, curve plot and etc.