分布式光纤传感中用于快速检测的软硬件设计

针对目前分布式光纤传感系统检测速度慢的缺点,利用可编程逻辑器件(FPGA)芯片为核心设计能快速检测的数据采集系统,将1次全量程检测时间从30 s甚至几分钟缩至10 s以内,使得分布式光纤传感接近实时. 分布式光纤传感技术是光纤传感中最有应用前景的技术之一,其最大的优点是能实现大范围超长距离检测.介绍布里渊和拉曼这两类分布式传感的传感原理以及其重复性、帧结构的传感数据特点. 根据该特点设计基于FPGA内部的多个先入先出（FIFO）的超长环形队列进行数据缓冲和求均算法操作,对信号进行降噪处理,并设计基于USB20协议的CY7C68013A数据传输模块将数据传输到上位机显示和存储. 结果表明,该设计解决了分布式光纤传感中因测量时间长,不能实时检测的问题,实现准实时检测,大大提高分布式光纤传感的性能,可应用于需要准实时监测和大量传感器的场合.

Hardware and Software Design for Rapid Detecting Property in the Distributed Fiber Optic Sensing System

A data acquisition system of the distributed sensing technologies is developed with rapid detection property using FPGA, for slow detection speed of a full-scale detecting of current distributed optical fiber sensing system. With our fast data acquisition system, the time consumption of a full-scale detection is suppressed to be less than ten seconds from 30s or even a few minutes, making it possible for the quasi real-time monitoring. Distributed fiber-optic sensing technology is one of the most promising fiber-optic sensor technologies. Its biggest advantage is the large range and long distance detection. Both of Brillouin and Raman distributed sensing principle and its repeatability, frame structure characteristics of the sensor data are introduced. According to these characteristics, long ring queue of a number of FIFO in FPGA are designed to buffer and average data, for signal noise reduction. Data transfer module based on USB2.0 of CY7C68013A is designed to transfer data to the PC for displaying and storage. Results showed that the design realizes quasi real-time detection, solving the lack of long time and not real-time detection. It greatly increases the performance of distributed optical fiber sensing. The proposed sensing system can be used in monitoring the power line systems, railway, subway tracks, tunnels, dams or landslide, where require real-time monitoring and a large number of sensors.