基于琼斯矩阵建模的管道泄漏检测及预警系统的定位误差分析

Locating Error Analysis in Pipeline Leakage Detection and Prewarning System Based on Modeling Using Jones Matrix

为了解决分布式光纤油气管道泄漏检测及预警系统中常出现粗大定位误差的问题,需要提高定位精度,在分析系统的检测定位原理的基础上,基于单模光纤的双折射特性等效琼斯矩阵,建立了油气管道光纤预警系统的光学偏振模型,并对模型进行了仿真。指出信号关联的二义性即两传感器获得同一振动源的波形不相关的现象,是造成粗大定位误差的原因。根据该理论模型,提出了利用外加偏振控制器改变激光偏振方向的解决方法,定位实验证明该方法较好地解决了上述问题,提高了现场实验的定位精度。该模型的建立,为预警系统光路的改进和调节提供了理论指导。

To eliminate the gross error in the distributed optical fiber pipeline leakage detecting and prewarning system and to improve the locating accuracy, based on the analysis on the detecting and locating principle, the optical polarization model is established which is based on the equivalent Jones matrix of the single-mode optical fiber birefringence. Model simulation shows that the cause for the gross error is the discrepancy of two signals, which means that the signals acquired by the photodetectors from the same vibroseis are not correlative. According to the theoretical model, the solution of using external polarization controller to change the polarization direction is put forward. It is proved by the experiment that the solution can solve the problem preferably and improve locating accuracy. Furthermore, a theoretical guidance of the system improvement and the adjustment in optical structure is provided based on the theoretical model.