Research On Dynamic Demodulating Technique For Fiber Grating Sensor System

Since its invention, FBG sensor has completed theoretic research and experiment demonstration, and becoming more widely used in many fields. Now the manufacture technology of FBG is reliable. So research field has focused to improving demodulation and multiplexing technology based on the reducing cost.The demodulation method of FBG is a critical and difficult problem in nowadays FBG sensor fields. The demodulation methods of FBG is the focus research and investigations in domestic and abroad, most of the researches are still in the phase of lab experiments and have a long way to go to the practical industrial mass productions. In the thesis, the demodulating techniques with Long period grating is discussed. The discussion as following:Firstly, the circs of the fiber grating is introduced simple, including manufacture technology, actuality researches etc. The demodulating techniques and the project for FBG with LPG are expounded and the basic theory of the fiber Bragg grating is introduced in this chapter, including the elements of coupling and sensor.Secondly, the demodulating techniques in domestic and abroad are introduced and comparing their characteristic.The demodulating techniques and the project for FBG with LPG are expounded. The each part of system is introduced detailed, including the circuit of PIN and signal disposal etc. These prepare the good signal for the NI 6024E. The software system aiming for data collecting is designed and realized with VC++ and LabVIEW. The effect of experiments can be observed clearly.Finally, the demodulating system is applied at the experiments of temperature and concussion. According to lots of experiments and data analyzing, the dependability and stability are proved.