Research On Continuous Distributed Optical Fiber Sensing Security System Localization Algorithm

With the rapid development of social economy, communication cables (including submarine cables), oil pipelines, gas pipelines, high voltage power grid, area and border security system and other infrastructures have become a an important factor of economic development and social stability. Especially in recent years, due to the factors such as illegal construction, natural disasters and man-made destruction have frequently leaded to pipeline leakage, high tension line theft and illegal invasion events. Not only to cause the people and the country’s economic and property heavy loss, but also to bring people’s life security and the environment great threat. Therefore, in view of the above situation, timely detection and effective positioning has important research value and practical significance.Relative to the electric signal and dot optical fiber sensing monitoring system, based on continuous distributed optical fiber monitoring system in this paper, we study whether it is from the difficulty of monitoring technology, monitoring contents and indicators, or from the monitoring of the situation and the range is increased to a new stage. The continuous distributed optical fiber sensor in addition to have a traditional optical fiber sensors’ prominent advantages, also can realize the continuous uninterrupted monitoring on the monitored environment, so it can constitute a continuously distributed sensor network, and applied to some of the traditional electric sensors and point fiber sensor application field. This paper deeply studies the continuous positioning principle of distributed fiber optic sensing network and algorithm, and according to the problem of the different outside bad environment influence on the continuous distributed optical fiber sensor demodulation system. This article main research content includes the following aspects.(1) Based on the Mach-Zehnder interferometric fiber optic sensor, the paper analyzes the continuous working principle of distributed fiber optic sensing network and positioning algorithm. And short-time zero crossing rate algorithm in speech signal processing is applied to the system, to eliminate the influence of the external environment (including rain, percussion, wind, etc.) on optical fiber security system, he implementation the location of artificial climbing action, and improve the positioning precision of the continuous distributed optical fiber sensing network, the data which are collected verify the effectiveness of the algorithm.(2) A field experiment platform for the fiber optic guardrail has been set up, according to the artificial climbing data collected from the field, based on BP neural network learning model, the system has completed to learn and train the artificial climbing signal short-time zero accumulation, then put the climbing signal zero crossing accumulation array after adding random noise signal into the BP neural network. Simulation implements the BP neural network adaptive adjustment of the noise threshold, and made the positioning precision in the original basis for further ascension.(3) The continuous distributed optical fiber sensor has been designed based on the NI Labview software platform, and completed to design and implement a data reading module, FIR digital band-pass filter module, algorithm module, the short-time zero crossing rate module, BP neural network module and the generalized cross-correlation algorithm. Finally established a set of continuous distributed optical fiber sensor security system based on the virtual instrument technology.