【作者】 史有刚；

【导师】 肖本贤；

【作者基本信息】 合肥工业大学 ， 电气工程， 2003， 硕士

【摘要】 本系统采用先进的微弱信号检测技术和现代信号处理技术，解决了低进站压力条件下泄漏负压波检测的难题，存在大量工业噪声的工况下，成功地检测出微弱的负压波信号。采用独特的信号自动分段技术和结构模式识别技术对泄漏进行判断，减少了误报率，提高了检测灵敏度。本系统基于对泄漏引发的负压波波形结构特征的深入分析，提出了三个反映压力波信号结构变化的三个主要的统计特征参数，并给出了信号进入异常段时的判定公式。 本系统将先进的小波变换技术引入负压波特征拐点的捕捉。利用小波变换的快速算法(Mallat算法)对泄漏负压波信号进行了多分辨率分析，同时得到了其低频概貌和高频细节。因此稳定地提取了负压波的拐点，提高了定位的准确性。本文应用负压波检测的方法，通过数学分析工具小波分析对采集到信号进行处理，建立原油泄漏的综合数学模型，并提出了一种新型的原油长输管道原油泄漏检测的方法。这种方法能够在较短的时间内采集到现场原油泄漏的数据，从而达到快速准确判断出原油泄露点的目的。与传统的检测方法相比，该方法的泄漏检测速度快，具有较高的定位精度、灵敏度和可靠性。更多还原

【Abstract】 This system, in which the advanced small-signal detection and modern signal processing techniques are introduced, has resolved a problem that it is difficult to detect the negative pressure wave caused by the leak of pipeline in the case of low oil pressure at oil stations and successfully detected small negative pressure wave signals in the presence of much industrial noise. And unique signal automatic segmentation and structural pattern recognition techniques are used to judge the leaks, which makes for a decrease in the rate of false alarms and an increase in the detection sensitivity. Based on in-depth analyses of the negative pressure wave structural features, this system brings forward three primary statistic characterization parameters reflecting structural changes of pressure wave signals, and provides a determinant formula for signals within abnormal segments.The advanced wavelet transform technique is introduced into this system to capture the Leak inflexions of the negative pressure wave. And the negative pressure wave signals are multi-resolution analyzed to obtain its low-frequency profile and high-frequency details. Therefore, the said inflexions are stably captured so as to improve the location accuracy. This paper introduces the negative pressure wave detection method and wavelet analyses, one kind of mathematic analysis tools, to process the captured signals. Then the integrative mathematic model is set up for oil leak detection and one new leak detection method is brought forward for oil pipelines, which can collect field data in connection with oil leaks in shorter time so as to achieve the goal of locating the leak points quickly and accurately. Compared with the traditional detection methods, this method is quicker in leak detection, more accurate in location, higher in sensitivity and more reliable.更多还原