Study On Signal Processing Of Fiber Alarm System With FBG

Fiber Bragg Grating (FBG) is one of the most potential and typical optical passive components at present. FBG can be immune from light source disturbance and system loss, because of it has the characteristic of wavelength coding. Besides, FBG is of good reliance, immune from electromagnetic signals and corruption, recently, demodulation technology of FBG is one of the difficult and critical problems in the fields of FBG sensing technique research. And it is also one of the current heat problems in the many research organization.The background of this dissertation is the widely apply of FBG sensor, and the subject is the research and design of FBG heat detect. The basic principles and theory module of the FBG heat detecting system were researched. The system design was completed, and improved the system features of anti-interference with programmable logic.Combining the function, the basic optics characteristic, FBG theory module, temperature sensor module were researched, and the temperature pressure cross module was analyzed more. It introduced fire disaster detecting technology, system structure and developing direction. Contrasting some fire disaster detecting technology, it showed the advantage of FBG heat detecting system.The application of identical fiber grating was presented. The system structure, MCU design, parameter storage, display, RS485 bus were given. And combining the characteristic of FBG heat detecting system, it completed the software. Then it analyzed the core arithmetic in detail.According to the specific features of PCB, it improved on the system with CPLD. Then, the design flow of CPLD based on Verilog HDL, and it analyzed detailed the need notice problem of condition, circle, finite state machine. The MC14499 model and I~2C bus was implemented. And corresponding emulator wave was given.The practical result showed it is stable and reliable. Basically satisfies the design request.