基于无线声发射传感网络的立体管网微泄漏实时监测方法研究

Acoustic emission technology has enormous advantages on leakage detection in oil, water, gas or steam pipeline networks, especially the micro leakage. This proposal is going to carry out the research on real-time monitoring of micro leakage in pressurized pipeline networks using wireless acoustic emission network. Through exploring propagation rules of acoustic emission stress wave produced by micro leakage in pressurized pipeline networks, a new idea of identifying the hit sequences of acoustic emission sensors is proposed to recognize the leakage section of pipeline networks. The separation and weaken algorithm on the acoustic emission stress wave echoes is proposed to eliminate echoes interfere during detection leakage. Meanwhile, in order to precisely eliminate strong background noise, a special wavelet basis function is built to strengthen wave features of leakage acoustic emission stress wave. The locating model of acoustic emission source is built to solve space coordinates of leakage point based on the cepstrum and correlation analysis. Furthermore, in order to provide the theoretical method and the enabling technology for the application of the wireless acoustic emission sensors network in real-time monitoring of micro leakage in pressurized pipeline networks, a method of high precise time synchronization with hardware for wireless sensor network based on Zigbee technology is proposed to realize synchronous functions. The regression model of the synchronization error of clock drift and software delaying is reveal, and the synchronization period is obtained.

声发射传感技术在探测易燃、易爆气/液体管道运输中的泄漏事故具有极大优势，尤其适用于管道微泄漏的早期预警。本申请拟开展“基于无线声发射传感网络的立体管网微泄漏实时监测方法研究”，通过探索多分叉路径下管网微泄漏声发射应力波传播规律，构造基于辨识多声发射传感器响应序列的立体管网微泄漏事故段识别算法；研究管道微泄漏应力波的回波传输机理及其分离与弱化算法，识破泄漏辨识中具有相似波形特征的回声欺骗，同时构造专用于泄漏事故波形特征增强的专用小波基，实现强背景噪声的精确分离，进而结合倒谱与互相关分析，构建泄漏事故段的声发射源定位模型，解算泄漏点空间坐标；构建分层式簇头型无线声发射传感网络，研究基于硬件触发计时的网络同步协议，揭示网络软件延时不确定性和节点晶振波动对同步精度的影响规律，提取满足同步精度的网络再同步对准周期，为无线声发射传感网络在立体管网微泄漏实时监测中的工程应用提供理论方法和使能技术支撑。

声发射传感技术在探测易燃、易爆气/液体管道运输中的泄漏事故具有极大优势，尤其适用于管道微泄漏的早期预警。本项目以“立体管网微泄漏的声发射实时监测”为研究对象，对管道微泄漏应力波的回波传输机理及其分离与弱化算法进行研究，优选出了专用于管道微泄漏声发射应力波强背景噪声分离的专用小波基，消除了回声和强背景噪声对管道微泄漏辨识的干扰；针对立体管网泄漏事故段泄漏源的定位，提出了管道泄漏源定位和定位与成像算法，并开发了便携式微泄漏检漏仪，实现立体管网泄漏事故段泄漏源实时检测的工程应用；结合多传感器实时监测网络拓扑结构的研究，提出了立体管网微泄漏实时监测的声发射传感器空间布局准则，以此构建立体管网微泄漏事故段的实时监测方法，可在剔除泄漏段的声发射应力波回声与强背景噪声基础上，实现泄漏事故段的识别。