The Study Of FBG Demodulation System Based On ARM9

FBG (Fiber Bragg Grating) sensor has stepped out of Invention, Production, Principle research,experimental test and into widly using in many fileds such as bridges,tunnels,dams,chemical industries,electric power,large mechanisms and so on, Now Engineering applications are developed to a certain extent. The demodulation technique of FBG is a critical and difficult problem in FBG sensors fileds.The quality of signal demodulation system performance is the main factors restraining the system design and application level of sensor. It is very important to develop some Demodulation equipment that can measure multi-parameter and meet specific requirements for special applications,as the multi-parameter sensing and distributed sensing features of FBG sensors.The FBG demodulation equipment is developing from the direction of Single wavelength demodulation to the direction of integrating wavelength demodulation, data calibration, data storage, health monitoring, multi-parameter diagnostic,which closely combined with special requirements.At present,most of demodulation equipments send wavelength data to demodulation software running on upper computer via serial line,USB data line or network cabling. The two-level structure can enhances the generability of demodulation equipment,but it also lowers the expertness, makes more difficult when debugging outdoor and it is not suitable for easily operated and easily carried.This paper is to design a portable and Specialty FBG demodulation equipment which is local processing,Iocal displaying,local operationg local storing and suitable for outdoor debugging,easily carried,user-friendly and easy to operate.To accomplish this task following work are mainly done based on a FBG demodulation equipment developed by Wuhan University of Technology.1.Analysis of the method and technique about how to detect and measure tiny excursion of the wavelength reflect from the FBG sensors:we choose to use the method of F-P demodulation considering the application requirements,performance,cost and other factors after summarizing and analyzing several methods of demodulation,especial introducing the F-P filter demodulation in detail.2. Hard design and software design for system:make Total Design and select ARM9 microprocessor produced by sumsang after the detailed design of needs analysis;analysis the system architecture of software and introduce how to design and develop Embedded System;choose Qt as User Interface and make outline design for embedded demodulation software.3.Embedded implementation of FBG demodulation:migrate embedded Linux operating system to ARM9 and implements the demodulation software, Man-Computer Exchange module and communication module.Make a Functional and Performance Testing and anaysis the testing results at last.