埋地管道泄漏三维坐标-波速联合估计方法

为实现埋地输气管道泄漏精确定位,使用加速度传感器在土表检测泄漏振动声波,并提出基于非均匀L形阵列的泄漏源三维坐标和波速联合估计方法。大孔径非均匀L形阵列内嵌小孔径L子阵,由小孔径子阵结合Root-MUSIC算法求解远场信源DOA与波速的约束关系,再利用大孔径L阵进行波速和近场信源距离的二维空间谱估计,最后根据估计结果计算三维坐标从而降低计算量。定位实验结果验证了L形阵列性能的优越性,基于L形阵列的联合估计法能够估计不同土壤条件下的泄漏振动声波传播速度,并得出泄漏源的三维坐标。相较于使用理论波速的定位方法,联合估计法定位误差降低了90.9%,避免了理论波速误差对定位的不利影响。联合估计法的计算耗时比直接三维空间谱估计降低了88%,且定位精度保持不变。根据远/近场判据计算出信源范围r_min～r_max,实验验证该范围内可实现精确定位。

A joint 3D coordinate and wave-speed estimation method for the buried pipe leak localization

To accurately locate the leak in the buried gas pipes, accelerometers are mounted on the ground to detect the leak-inducedvibroacoustic waves. A new method using nonuniform L-shape array is proposed to jointly estimate the 3D coordinate and wave-speed. Asmall-aperture L-shape subarray is embedded into the large-aperture L-shape array and is combined with the Root-MUSIC algorithm tofind the relationship between DOA of far-field source and wave-speed. Then, the large-aperture L-shape array is used to perform 2Dspatial spectrum estimation for wave-speed and near-field source distance. Finally, the 3D coordinate is calculated using the estimationresults and the computational complexity is reduced. The results of localization experiments show a superiority performance of the usedL-shaped array. The joint estimation method based on the L-shaped array can estimate the propagation speeds of leak-inducedvibroacoustic waves in multiple soil conditions and the 3D coordinate of leak source is derived. Compared with the localization methodusing theoretical wave-speeds, the error in joint estimation method is reduced by 90. 9% , which avoids the influence of error intheoretical wave-speed on localization. Compared with the direct 3D spatial spectrum estimation, the calculation time of the jointestimation method is reduced by 88% and the localization accuracy remains well. The range of signal source, rmin ~ rmax, is calculated byusing the far-and near-filed criteria. Experiments evaluate that accurate localization can be achieved within this range.