管道运输地面信号检测标记器电路设计研究

The Design and Simulation of Signal Processing Circuits of Pipeline Inspection Ground Marker

管道运输地面信号检测标记器是管道缺陷检测系统的一部分,主要用于捕捉微小漏磁信号以消除累积误差,达到减小缺陷定位误差的目的。由于漏磁信号十分微弱,对其的准确捕捉成为难点。因此需采用高精度的巨磁阻传感器对信号进行捕捉并设计适合此微弱信号的处理电路。利用Multisim电路仿真软件实现此电路的仿真设计。电路设计由信号前置放大、低通滤波和信号电平转换电路组成,用模拟信号代替巨磁阻传感器采集到的信号,对其进行的一系列处理。仿真结果表明,系统达到了对信号放大和滤波的目的。

As part of the inspection system based on the magnetic- flux leakage（ MFL）,the Above Ground Marker is mainly used to capture the small signal of MFL to eliminate the accumulated error and reduce the defect positioning error. Capturing the MFL signal accurately is very difficult since the signal is weak. Therefore the magnetic sensor of high- precision to capture signal of MFL and the circuits of signal processing are required. The associated signal processing circuits are simulated by using the simulation software Multisim. The circuits comprise a signal pre- amplification,low- pass filtering and signal level conversion module. Analog signal replaces the signal of MFL,it reachs signal amplification and filtering by a series of processing systems.