基于球形内检测器的管道内磁场测量

球形管道内检测器在管道安全检测领域具有十分广阔的应用前景，但其在滚动过程中测得的磁场信号呈周期性，无法直观反映管道内磁场分布情况，给识别焊缝和计算管道走向带来了一定的困难。针对此问题本文推导了滚动坐标系下球形内检测器测得的磁场与管道内平动坐标系下磁场之间的数学关系，并利用处于同一滚动坐标系下的加速度信号构建了转换模型，然后设计实验和算法验证了模型的正确性。实验结果表明，平动磁场的计算值和实测值在数值大小和变化趋势上均吻合良好，误差绝对值的平均值基本不超过1μT。

In-pipe magnetic field measurement using spherical inner detector

Spherical inner detector has a board application prospect in pipeline safety detection. However ,due to the detector’s rotation,the collected magnetic field signal is always periodic,which cannot reflect the actual condi?tion of the in-pipe magnetic field directly and makes it difficult to calculate pipelines’orientation or discover the welds. A method is proposed to transfer the collected magnetic field signal in the rotating sensor frame to which in the stationary pipe frame. The relationship between them is deduced,and the mathematic model is built using the collected acceleration signal in the same rotating sensor frame as the acquired magnetic field signal. Experiment and algorithm are designed to verify the correctness of the model. The results show that the calculated magnetic field is in good agreement with the measured magnetic field both in value and trend,while the average of error’s ab?solute value is almost within 1μT.