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漏磁式管道内检测器广泛应用于长距离输油管道缺陷检测中,声学地面标记器作为管道外定位装置的重要组成部分,具有重要的研究价值.然而当管道埋地深度超过4 m时,由声学地面标记器采集到的管道内检测器与管道的摩擦声信号被噪声淹没,不能提取定位信息.为了解决摩擦声信号信噪比低的问题,提出采用声传感器阵列技术对摩擦声信号进行增强.根据管道内检测器与管壁摩擦声的特征,研究合适的时延估计方法,精确得到几路传感器的时延,再利用延迟-相加波束形成的方法抑制噪声,提高摩擦声的信噪比,增加基于摩擦声的地面标记方法的检测深度.为了验证声传感器阵列对管道内检测器摩擦声信号的增强效果,在河北廊坊中石化管道局的2.5 km长管道上进行多次现场实验,实验结果表明延迟-相加波束形成算法能够将摩擦声的信噪比提高了20 d B,并且有效的埋地管道检测深度可增至8 m.
Magnetic flux leakage detector is widely used in long-distance pipeline defects detection, acoustic ground marker as an important part of pipeline positioning device has important research value.However, when the pipeline buried depth of more than 4 m, from In order to solve the problem of low signal-to-noise ratio of friction acoustic signal, the acoustic signal array of acoustic sensor array is proposed to enhance the friction acoustic signal According to the characteristics of the frictional sound between the detector and the pipe wall in the pipeline, the appropriate time delay estimation method is studied, the delay of several sensors is obtained accurately, and then the delay-additive beamforming method is used to suppress the noise and improve the signal noise , And increase the detection depth of ground mark method based on fricative sound.In order to verify the enhancement effect of acoustic sensor array on the acoustic signal of the detector in the pipeline, several field experiments were carried out on the 2.5 km long pipe of Langfang Sinopec Pipeline Bureau, The results show that the delay-sum beamforming algorithm can improve the signal to noise ratio of friction sound by 20 d B, and the effective buried pipe Road detection depth can be increased to 8 m.