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Design On Interrogator System For Distributed Fiber Bragg Grating Sensors Based On Arrayed Waveguide Grating

Posted on:2010-02-13Degree:MasterType:Thesis
Country:ChinaCandidate:D D YuFull Text:PDF
GTID:2178360278466640Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
At Present single FBG (Fiber Bragg Grating) sensor technique has been developed rapidly. However a large number of sensors are needed for structures' monitoring and controlingin large-scale projects. For example at least 5000 sensors are necessary to monitor an airplane's construction. Therefore single FBG sensor can not fulfill these practical needs. Now people start to pay more attention to the distributed FBG sensing system.In order to improve the interrogating speed and the sensor multiplexibility for the FBG sensors system, on account of the arrayed waveguide grating (AWG) has the advantages include flexible designed, good filtering characteristics and stable performance for long term and so on, an novel interrogator for distributed FBG sensors that employs an arrayed waveguide grating is proposed. Account to the actual situation and the system specific requests, it is supposed to take Altera Corporation's CPLD EPM7128S as the control core, AD1674 as the signal gathering chip, and realize the double-channel parallel synchronization gathering multi-channel data. The data gathersed is transmitted to the computer through the main line to carry on processing, result display and the memory, and the system software can show the sensing result dynamically.The thesis tested the theory from two aspects to confirm this method's feasibility, and carried on the software and hardware design of signal gathering and data processing in the system. According to the interrogator theory, the wavelength shift of fiber grating is acquired by detecting the current variation of corresponding photodiodes which implement of various physical measurements. Experiment results show that the system has carried out the fast interrogator and the number of grating multiplexed is greatly increased. The system is suitable in each kind of sensing quantities in the distributed measurement, such as for temperature, strain, pressure and so on.
Keywords/Search Tags:arrayed waveguide grating, distributed, fiber Bragg grating, wavelength demodulation
PDF Full Text Request
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