A Design Of Signal Processing Unit For Optical Fiber Vibration Monitoring System Based On Arm And FPGA

Distributed optical fiber vibration sensing technology uses features of fiber optic to detect changes in environment. This new type sensor overcomes the shortcomings of traditional point-type sensor, with small size, anti-radition, corrosion resisting and many other advantages. As distributed optical fiber vibration sensing technology can do a wide range of intrusion detection in a remote, continuous and real-time way, it can be widely used in the field of perimeter security, especially in infrastructure which has special security requirements.This paper focused on the applications of distributed optical fiber vibration sensing technology in the field of perimeter security. By developing the signal acquistion and processing part of the system, this paper has acquired the sensing signal, done the vibration signal recognition, built a friendly interface to users.Based on the characteristics of the distributed optical fiber vibration sensing signal, this paper introduced the ARM(S3C2440)+FPGA(EP4CE55) collaborative processing architecture, made full use of the real-time and parallelism of FPGA to control optical hardware, acquire sensing signal and do the data’s pre-processing. Sensing data is read and recognised in perimeter security monitoring software system that is developed for Linux OS,which is ported to ARM cpu. The main work is as follows:First, by using the architecture of FPGA base board+ARM core board, this paper has done the schematic and pcb design for the dual-channel data acquistion and processing board, including power distribution part, data acquistion part, FPGA/ARM with their peripherals and so on.Second, digital design is done in FPGA for controlling ADC, caching data and communicating efficiently with ARM. FPGA is simulated as a bus peripheral of ARM. By implementing registers and FIFOs inside FPGA, ARM can easily configure the data acquistion process and get cached data using bus write/read command.Third, Linux device driver is designed in ARM for bridging Linux user-layer applications with FPGA hardware, including command/data communicating, interrupt handling as well as providing concise APIs for Qt application. According to the application scenarios of intrusion detection, Linux-2.6.32 kernel and YAFFS file system are ported to S3C2440.Tests in laboratory showed that hardware and software worked well and this design did a good job for supporting intrusion detection and locating.