FBG Vibration Detection Based On ARM Embedded System

In highly developed modern society, more and more engineering applications need analysing and processing vibration signal information. Dealing with the vibration problem accurately would be helpful to design precision instrument and safety buliding structre, by reducing the negative impact from vibration. Currently, traditional electrical measurement is the main approach to vibration detection. However, this approach need extra attention to system insulation and electromagnetic interference (EMI). These defects result in the application being limited on the occasions which requires a higher security. With the advantages of simple structure, high sensitivity, intrinsic safety, anti-electromagnetic interference and wavelength multiplexing capability for sensor networking, fiber Bragg grating sensors have become one of the fastest developing sensing device in recent years.In this thesis Fiber Bragg Grating Vibration Detection Embedded System is designed for vibration detection in complex environment, based on research of the fiber Bragg grating sensing technology and embedded technology. The main contents are listed as follows:Firstly, analyze the principle of fiber grating sensor using the fiber grating coupled-mode theory. Then fiber Bragg grating acceleration sensor is designed to measure vibration based on the principle. By comparing the fiber grating sensor demodulation technique, a optical system based on matching filtering demodulation technology is designed and experimented.Secondly, signal process circuit is designed to change small optical signal into electrical signal. The signal process circuit includes photoelectric conversion circuit, signal amplify circuit and filter circuit, etc. Because optical signal in fiber Bragg grating sensor system is too weak, effective measures for interference suppression are necessary to ensure the accuracy and stability of the fiber Bragg grating sensor system.Thirdly,μC/OS-Ⅱreal-time embedded operating system is used to develop application program based on LPC2210 ARM processor combined with peripheral equipments. Signal acquisition function, human-computer interaction function and PC communications function are complied in the novel system. The use of embedded technology makes the vibration detection system has digital, intelligent, networking.Finally, test platform is established by laboratory resources. The entire system is tested and the stability and reliability is proved by using the Steady-state sinusoidal excitation method and transient excitation method.