在单光纤对光耦合模型的基础上, 研究了三种带补偿功能的三光纤反射式位移传感器, 建立了通用的光耦合的数学模型。仿真研究了它们的位移特性, 并比较了它们的优缺点。研究结果表明, 采用三光纤的光纤位移传感器不但线性范围、位移灵敏度和线性度等特性得到较好改善, 而且可以有效地消除光源功率波动和反射面的反射率变化等因素对位移测量的影响。 关键词: 光纤传感器; 数学模型; 位移特性; 强度补偿; 反射率补偿 中Abstract : In the field of reflective fiber2optic displacement sensor , in order to improve the displacement measuring accuracy , two receiving fibers are often used for intensity and reflectivity compensation. Based on the mathematic model of light coupling between the fiber pair , three types of tri2fiber optic sensors are studied. The general mathematic model of the tri - fiber sensors is proposed. Simula2 tion about them is finished. Research shows that these kinds of tri2fiber sensors can not only improve the linear range , linearity and dis2 placement measuring sensitivity , but also eliminate the influence caused by power fluctuation of the light source and variety of surface re2 flectivity. Key words : fiber optic sensor ; mathematic model ; displacement ; property ; intensity compensation ; reflectivity compensation