Research on Distributed Optical Fiber Pipeline Micro Leakage Detection Technology Based on Recursive Least Square

A very weak vibration signal is generated when the pipeline leaks slightly. However, the commonly used pipeline leakage detection technology cannot obtain this kind of signal normally, thus causing large positioning error. Aiming at the above problems, a pipeline micro leakage detection technology based on Recursive Least Squares distributed optical fiber is proposed. The technology utilizes a dual Mach-Zehnder interference system with high sensitivity and simple optical path structure to monitor the interference signal caused by pipeline micro leakage at all times. Then, the adaptive filter based on Recursive Least Square method is used to denoise the interference signal. On this basis, the cross-correlation algorithm is used to obtain the delay estimation of the two test signals. This article clarifies the positioning principle of the detection technology and conducts the positioning experiment of pipeline micro leakage. The experimental results show that this technology can effectively detect the weak vibration signal generated by pipeline micro leakage and greatly improve the positioning accuracy of micro leakage points. The relative error can be controlled within 1%.