Design Of Fiber Grating Monitoring System Based On FBGA Demodulation Module

FBG as a sensor because of small size,light weight,variable shape,suitable for embedding large structures,can measure the structure of the internal stress,strain,structural damage,and has good stability,corrosion resistance,anti-electromagnetic interference characteristics.Suitable for working in harsh environments;can write a plurality of gratings in one fiber to realize distributed sensing;The measurement information is wavelength coding,which is not affected by the light intensity fluctuation of the light source,and has strong anti-interference ability.Because of these advantages,fiber grating sensors in a large civil engineering structure,energy and chemical industry,aerospace,biomedical and other fields has been widely used.Firstly,the development history of fiber grating and the advantages and disadvantages of fiber grating as sensor are introduced,as well as the structure of FBG,the fiber bragg grating demodulation methods,the characteristics of each type of demodulation method is given.And the application fieldsof fiber grating in sensing field is introduced.Secondly,the hardware module of the hardware platform is selected and the parameters of the corresponding module are introduced.Considering the problems that may arise in the actual engineering application,the hardware platform of FBG demodulation based on FBGA demodulation is built.Thirdly,the software program of the temperature detection system is written by calling the underlying dynamic link library of the module,including the initialization program,the continuous acquisition program and so on,and the temperature detection system is tested and verified.The result of the experiment is compared with the measurement result of the high precision thermostat,verify the feasibility of the system.The results show that the temperature difference of the temperature detection system is less than 0.5℃.When the confidence probability is 95.40%,the repeatability indexRe is ?0.0210%.In addition,the software of the fiber grating impact detection system was designed,including high-speed impact data continuous acquisition program,high-speed data storage program,and carrying out experiments of the impact detection system,selecting the ideal silicone-based package as a sensor.The experimental results show that the impact detection system designed in this paper is feasible,in which the peak wavelength error of the impact detection system is less than 0.05 nm,and the response time is less than 0.1s.Based on the understanding and analysis of FBGA demodulation module,this paper uses the method of calling the underlying dynamic link library to editing the corresponding testing software,and verifies the feasibility of the method throughsimulation and experimental research.And laying the foundation for the development of economical and practical FBG detection system.