金属掩埋物的主动磁探测方法

Method of active magnetic detection for metal burial

目前金属掩埋物的探测多使用被动探测的方法,但被动探测存在基线漂移的问题,易产生探测误差导致误判。针对这一问题该文提出一种基于主动式的磁探测方法,探测系统主动向外辐射特定频率的信号,当信号照射在金属目标上时,会在金属上产生涡电流,进而形成涡流二次场向外辐射反射信号,当反射信号被磁传感器检测到时,即可确定该处存在金属掩埋物。针对探测过程中反射信号与直接耦合信号重叠问题,采用合理天线配置与自适应对消技术予以抑制直耦信号的影响,极大程度上提高反射信号的检测信噪比。最后成功进行空心铁管的0.5 m掩埋物探测试验,试验结果表明该探测方式可以很好地探测到金属目标物,具有较好的工程应用前景。

At present,the detection of metal burial mostly uses passive detection methods,and passive detection has the problem of baseline drifting,which is prone to misjudgment.Aiming at this problem,this paper proposed an active magnetic detection method.The detection system actively radiated specific electromagnetic signals.When it was irradiated on a metal target,the eddy current would be generated on the metal,and then the reflection signal of the secondary field of the eddy current would be radiated outward.When the reflected signal was detected by the magnetic sensor,it was possible to determine the presence of metal buried objects.To solve the problem of overlap between reflected signal and directly coupled signal,a reasonable antenna configuration and adaptive cancellation technique were adopted,which was good to improve the signal-to-noise ratio of the reflected signal.Finally,the 0.5 m burial detecting test of hollow iron pipe was successfully carried out.The test results showed that this method can detect metal objects very well,and has good engineering application prospects.