Study On High Speed FBG Demodulation System Based On ARM

Since its invention, FBG sensor has completed theoretic research and experiment demonstration, and becoming more widely used in many fields. Now reliable FBG technology can manufacture volume-produce FBG So research field has focused to high-precision application, improving demodulation and multiplexing technology and reducing cost. On the other hand, because FBG sensor combines transfer and senor , it can has many sensor element in an optic fiber. So distributed sensor is fiber sensor's inherent merit.The demodulation method of FBG is a critical and difficult problem in nowadays FBG sensor fields. Although a large number of research units in domestic and abroad have been done a lot of research and investigations on the demodulation methods of FBG, 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.The fiber grating sensor theory and technology are systematically researched in this paper. The main content includes: the principle of fiber grating sensor; the analysis of several methods of demodulation and the F-P filter demodulation is introduced in detail; the design of demodulation system based on ARM; the signal's real-time display; using USB protocol to transfer and save the data.Signal process and embedded system based on ARM are the current heat research fields. ARM has many merits such as high operation speed, low power consumption, abundant interfaces , can run embedded real-time operating system, and etc. Our demodulation system demodulates signal with ARM, and has many merits: First, high process capability improve the signal demodulation's precision and speed; Second, abundant interfaces make the demodulation system has a good man-machine interface, such as LCD display, keyboard input. Third, decreases the system's cost because ARM integrates many components.USB protocol is widely used in signal process and data acquision system since its high data transfer speed and plug and play. The system transfers demodulation data to computer's harddisk with USB interface, and convenient to analyze these data later. Its high data transfer capability can make the system apply to multiple signal process system.This demodulation system also has serial port, parallel port , JTAG port, and can display signal wave in LCD. So the system can not only demodulate FBG signal, but also provide a good human-machine interface, and convenient to using.