Based On Chirp Modulation Signal Of Fiber Bragg Grating Sensor Syetem

Fiber Bragg Grating(FBG) has a lot of advantages and its application is very widely in sensing filed. Sensing signal demodulation technology is a very important part for the application of fiber Bragg grating sensing network system, but has some problems such as low multiplex rates, high cost and others issues. The purpose of this dissertation is to design a low-cost, high multiplexing capability and high-precision fiber Bragg grating sensing network system to promote the practical development of the fiber Bragg grating sensing system.In the section of the fiber Bragg grating sensing networks system theoretical, we analyze the fiber Bragg grating sensing mechanism and introduce the advantages and disadvantages of several common multiplexing and demodulation techniques. According to code division multiple access fiber Bragg grating sensor network technology, we introduce a fiber Bragg grating sensing network system based on chirp modulation signal. This method inherits the advantage of the original network system, such as high reuse rates and high signal-to- noise ratio(SNR), and then the chirp signal modulation could solve the problem of the adjacent fiber Bragg grating time delay at least one cut spectrum timer.In the network system design and development section, we describe the theoretical principles of cross-correlation algorithm, and we use the Mulitisim simulation software to verify the reliability and validity of the algorithm in the process of addressing and demodulation. And then we design, produce and debug the hardware circuit of system. At last,we develop the part of data acquisition and processing of system software. Finally, we get a complete a fiber Bragg grating sensor network system based on chirp modulation signal.We design an experiment to measure stress based on the network system in experiment research part. According to the results of stress measurement, the system could measure stress accurately, and the accuracy of the system is 3.5pm. In order to improve the accuracy, we a nalyze the error sources in the entire sensing network system. We find few problems about the system and put forward some solutions according to the results of analysis.In the paper, we design and develop a system based on chirp modulation signal, and then we get the accuracy of the system through the stress measurement experiment. The fiber Bragg grating sensing network technology has low price, multiplexing capability and reliability advantages, and may improve the development of the sensing network system in the future.