基于光强余弦分布的同轴型光纤位移传感器设计

在分析了发射光纤出射端光强分布的几种模型基础上,提出了光强余弦分布的假设,并据此建立了单光纤对数学模型,设计出用于叶轮泵转轴径向跳动测量的同轴型光纤束位移传感器,建立了光纤束传感器调制函数的数学模型,仿真分析了传感器的输出特性。对测试系统稳定性进行了动态测试,结果表明:在转轴转速保持5 000 r/m in时,5m in内其稳定性优于±10μm,满足设计要求。可见发射光纤出射端光强余弦分布假设与实际相符,对光强调制型光纤传感器的设计具有指导意义。

Design of coaxial optical fiber displacement sensor based on cosine distributing light intensity

The hypothesis of cosine distributing light intensity is put forward based on analyzing several models of emitting fiber light intensity distribution.Single-fiber mathematic model is founded and coaxial optical fiber bundle displacement sensor is designed for measuring radial runout of impeller pump rotor.And the mathematic model of fiber bundle sensor modulating function is set up and output characteristic of the sensor is emulated and analyzed.The result of dynamic testing for the stability of the system indicates that the stability within 5 min is better than ±10 μm for 5 000 r/min,which meets the design demand.It is obvious that the hypothesis of cosine distributing light intensity meets the practice,which has guiding significance for the design of intensity modulated fiber sensor.