基于模型突变检测的管道泄漏检测定位方法

Method for Pipe Leak Detection and Location Based on Model Change Detection

为了改进负压波法在管道微弱泄漏的检测和定位中的效果,提出了基于模型突变检测的特征提取和泄漏定位算法。首先运用广义似然比检测理论,建立压力信号变化的统计检验模型,计算广义似然比比率r和下降幅度d作为压力信号突变发生的敏感特征,并通过求得的压力变化时间点进行泄漏定位。针对缓慢泄漏时压力信号变化的特点,提出了相应的改进模型,更精确的求出缓慢泄漏压力信号的下降拐点。实验证明,参数r和d对不同变化类型的压力信号有较好的区分度,利用管道内压力和流量信号的特征值作为神经网络的特征向量可以实现管道的微弱泄漏识别,且基于改进模型的定位算法在缓慢泄漏定位中有较好的定位结果和稳定度。

A novel method based on model change detection is proposed to improve the accuracy of conventional negative pressure wave method in small leak detection and location.The statistic test model of pressure change is built.Then the gen-eralized likelihood ratio “r”and the drop of pressure amplitude “d”are calculated as sensitive characteristics to the small change of pressure wave.The negative pressure wave inflexions are extracted by the estimated jump time of pressure wave. A modified test model is applied to locate weak singularities in small leak signal more precisely.The simulating test and field experiment show that characteristics r and d have a good performance in distinguishing different kinds of pressure sig-nals,and the locate algorithm based on modified model can accurately locate weak leaks.