Up to the principle of conventional fiber Bragg grating (FBG) sensors, we investigate a matched-FBG based demodulation scheme that can be used as the track sensor. According to the proposed strain sensing method using two matched FBGs and theoretical analysis of track strain distribution under load, we design a track sensor that can detect the local axial strain. The concept of the sensor is verified on the railway load test platform. Results under different environmental temperatures and load frequencies indicate that the matched-FBG approach can effectively solve the temperature and strain induced cross sensitivity problem, therefore it can meet requirements of axle-counting in rail systems. Such design may be a good candidate for constructing WIM systems as well.%通过光纤布拉格光栅( FBG)的传感原理研究基于匹配光栅解调的轨道传感器问题.依据匹配光栅检测应变的原理和列车载荷作用下钢轨应变分析,设计出一种检测钢轨局部轴向应变的光纤光栅轨道传感器方案；使用列车载荷模拟平台,对研制的轨道传感器功能进行了验证.不同环境温度、不同加载频率下采集到的实验数据表明:匹配光栅的解调方法能有效地解决温度应变交叉敏感带来的问题,满足对列车计轴的要求；并在构建交通动态测重系统(WIM)方面有好的发展前景.
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