准分布式光纤振动传感系统信号增益均衡及稳定技术

Gains Equalization and Stabilizing among Different Channels for Quasi-Distributed Optical Fiber Vibration Sensor System

针对准分布式光纤振动传感系统的各传感通道的增益差异,提出一种基于PI算法的多路信号增益均衡及稳定技术。通过合理设置算法的调节时间,确保传感系统正常工作的同时,消除了因光波偏振、相位等参数缓慢变化引起的增益变化。实验结果表明,四通道的复用系统,不同通道的最大增益差是1.6 V;每个通道增益波动幅度最大是2.3 V,波动周期是0.23 h。选取合适的PI控制器参数KP=0.01,KI=0.1,此时,PI算法的调节时间大约为4 s,增益波动幅度小于0.2 V。

Aiming at the difference of gains among the different channels for the quasi-distributed optic fiber vibra-tion sensor system,a method of gains equalization and stabilizing among different channels is purposed and imple-mented based on the PI arithmetic. Through figuring out a reasonable adjust time for the arithmetic,this method could eliminate the shift of the signal gain due to the slow fluctuation of the light polarization ,phase,and other pa-rameters with no influence of the vibration detection. Experimental results demonstrate that,the maximum gain dif-ference of different channels is 1.6 V,the highest fluctuation of each channel is 2.3 V with the period of fluctuation is 0.23 hour. Figuring out a reasonable parameter for the PI controller with KP=0.01,KI=0.1,as a result,the adjust time of PI arithmetic is about 4 s with the fluctuation of the amplitude less than 0.2 V.