在各类大型基础设施的安全检测过程中,应变作为一项重要的参数需要重点检测。为了准确测量一定范围内应变分布,提出了基于光频域反射技术(OFDR)的光纤连续分布式定位应变测量传感方法。这种方案根据瑞利散射光谱移动的原理,采用距离域移动窗互相关的光谱漂移解调算法来获取连续分布式的应变参量。实验结果表明,这种方法可以对100 m范围内光纤所受应变的大小及其分布位置进行稳定而有效的传感,系统空间定位分辨率为20 cm,相较于其他传感方式,这种方法既实现了对应变的定量检测,同时也获取了应变的空间分布信息,实现了应变的定位功能。
In the process of the safety text of the large infrastructure, strain is an important parameter which needs to be mainly detected. In order to measure the distribution of strain accurately, a method which is a continuous distributed fiber strain measurement sensing based on optical frequency domain reflectometry (OFDR) is presented. The method is on the basis of the principle of wavelength shifts of Rayleigh scattering and a demodulation algorithm of wavelength shift based on the movement window cross-correlation in spatial domain is used to gain the information of continuous distributed strain. The experimental results show that it can realize stable and effective stain sensing including the size and position in a range of 100 m whose sensing resolution can reach 20 cm. Compared with other sensing methods, it not only can text the strain quantificationally, gain the spatial information of the strain distribution, but also achieve a function of strain location.