Study On FBG Demodulation System Based On Single-chip

Fiber Bragg grating (FBG) sensor, which use the property that the Bragg wavelength is sensitive to temperature and the strain, is a new kind of fiber optic sensor .in addition to having the same function as the traditional electronic sensors, the FBG sensor also has some special characteristics such as immune to electromagnetic interference long-stability. So it is widely applied in many fields such as the structure monitoring of the large compound material and the concrete, the performance monitoring of the intelligent materials, electric power industry,fire fighting, chemical engineering etc. The demodulation technique of the FBG sensor is currently a critical and difficult problem in nowadays FBG sensor technique fields, and it is also one of the current heat problems in the many research organization.Firstly, the recent developments in the area of optical fiber grating sensors are reviewed. The method of fiber grating fabrication is introduced briefly. The principles which FBG is sensitive to temperature and the strain are introduced.The demodulation method of fiber grating is the key technology of fiber grating sensor. So combining and comparing with other various demodulation methods, the tunable Fabry-Perot cavity method is adopted, a demodulation system based on two MCU( AT89C52) is put forward, and the demodulation software is also designed.The demodulation arithmetic of system based on the identical fiber grating is introduced in the thesis, which is successfully experimented on the single-chip AT89C52.On the other hand, the interface display circuit is also designed in the system.At the time this system can display the highest temperature through LED and real-time alarm. Nowadays, the demodulation system is successfully applied to the fiber optic heat detectors field.Secondly, to implement the speed and accuracy of demodulation of fiber grating, The demodulation system based on ARM is designed in this article. In this paper, the Bootloader in ARM system, the transplantation of embed real-time OS, and the development based on the μC/OS-II OS are introduced.