一种大量程光纤弯曲损耗型线性位移传感器研究

Research on an Optical Fiber Linear Displacement Sensor Based on Bending Loss for Use over Large Range

针对很多大型工程结构存在大变形但仍可以发挥功能性作用的特点,基于光纤弯曲损耗传感原理,设计了一种可用于位移测量的大量程、结构简单的线性传感器。从理论上证明了测量位移与光纤弯曲损耗之间的线性关系,并推导出表达式,开展了一系列标定试验和性能试验。试验结果表明,该传感器的测量范围为0~200 mm,灵敏度为0.1668 dB·mm^-1,最小分辨位移为0.06 mm,重复性误差为0.26%,迟滞性误差为2.22%。所设计的传感器可用于结构的开裂测量和大型工程的连续监测,具有良好的应用前景。

It is the truth that many large-scale engineering structures have large deformation while they are still functional.Based on the bending loss characteristics of an optical fiber,we present a large range and linear sensor with simple construction for displacement measurement.The linear relationship between the measured displacement and the bending loss of an optical fiber is proved theoretically,and its expression is derived.A series of calibration experiments and performance tests are conducted.The experimental results show that the sensor is characterized by a wide measurement range of 0--200 mm,a sensitivity of 0.1668 dB·mm^-1,a minimum displacement resolution of 0.06 mm,a repeatability error of 0.26%,and a hysteresis error of 2.22%.The designed sensor can be used for the crack detection and the continuous monitoring for large-scale engineering structures and has a promising application prospect.