合成多频磁感应信号同步激励-检测方法研究

Research on Synchronous Excitation and Detection Method for Synthetic Multi-frequency Magnetic Induction Signals

磁感应检测技术是一种非接触、无创的电阻抗检测技术,多频率同步检测可同时获得不同频率下被测对象的阻抗信息。该文首先研究了磁感应信号多频率同步激励与检测原理,基于Walsh函数合成了5频率激励信号。其次分析了合成多频率同步检测性能,设计了合成多频磁感应信号同步检测系统。最后,通过合成5频率激励信号与同步检测系统进行不同电导率NaCl溶液的检测实验,结果表明:合成5频率激励信号5个主谐波的测量结果都具有很好的线性度,为磁感应信号多频率同步检测提供了激励-检测方法。

Magnetic induction detection technology is a non-contact and non-invasive electrical impedance detection technology.Multi-frequency synchronous detection can simultaneously obtain the impedance information of the tested object at different frequencies.Firstly,the principle of multi-frequency synchronous excitation and detection of magnetic induction signal are studied.Five-frequency excitation signal is synthesized based on Walsh function.Secondly,the performance of synthesized multi-frequency synchronous detection is analyzed,and a synthesized multi-frequency magnetic induction signal synchronous detection system is designed.Finally,the detection experiments of NaCl solution with different conductivities are carried out by synthesizing five-frequency excitation signal and synchronous detection system.The results show that the measurement results of five main harmonics of synthesized five-frequency excitation signal have good linearity.It provides an excitation-detection method for multi-frequency synchronous detection of magnetic induction signal.