不同于以往温度、应变与光纤Bragg光栅(FBG)峰值波长偏移量之间的数学模型,本文提出利用支持向量机(SVM,support vector machine)补偿温度的影响,并以FBG压力传感器为例,利用标定的压力传感器数据对SVM模型的惩罚系数C和径向基核函数(RBF)核参数γ进行优化,得到SVM温度补偿模型,选择核参数γ为100、惩罚系数C为16。经过补偿后,压力传感器的零位温度系数和灵敏度温度系数由补偿前的34.5%/℃和34.2%/℃减小到1.7×10-5%/℃和7.7×10-5/%/℃。充分说明,利用SVM补偿温度对FBG压力传感器的影响是有效的。
Temperature and strain are two parameters which are both sensitive to FBG sensor.Different from traditional model between temperature or strain and drift of Bragg wavelength,a method based on support vector machine(SVM) is presented in this paper.As an example,a SVM compensation model of pressure sensor is built.The parameters of SVM model are optimized based on the calibrated the kernel parameter of which is 100 and the penalty factor is 16.The compensation result shows the temperature coefficient of the pressure sensor data of the FBG pressure sensor,comes down from 34.2%/℃ to 7.7×10-5%/℃.It fully reveales that SVM is an effective method to compensation temperature.It also can be used for simultaneous measurement of temperature and pressure or other measurands which can be converted to strain.