RLC Parameters Measurement and Fusion for High-Sensitivity Inductive Sensors

In this article, an equivalent conversion between eddy current (ECT) sensor topology circuit and piezoelectric crystal topology circuit is proposed. Based on this conversion, a novel multiparameters separation method is designed to identify the inductance, capacitance, and resistance of the ECT sensor topology circuit though frequency-domain response in resonant status. The inductance and capacitance measurement accuracy of the proposed method is validated by COMSOL simulation through the proposed virtual vector network analyzer (VNA). Then, experimental results show that the inductance measuring by the proposed method holds exactly consistent with commercial instruments, whose error is as less as 3%. Each parameter (rather than partial parameters) of the ECT sensor topology circuit can be identified by the proposed method. Compared to traditional ECT sensors, the proposed method provides additional parameters as capacitance value in characterizing both winding capacitance and coaxial cable capacitance and resistance value characterizing conductivity variations due to crack or stress. Moreover, multiparameter evaluation provides the possibility for parameter fusion, and the signal-to-noise ratio (SNR) or sensitivity of ECT sensors in crack detection can be significantly improved.

Automated summary

This article proposes an equivalent conversion between eddy current sensor topology circuit and piezoelectric crystal topology circuit. Based on this conversion, a novel multiparameters separation method is designed to identify the inductance, capacitance, and resistance of the ECT sensor topology circuit through frequency-domain response. Experimental results validate the accuracy and consistency of the proposed method, which also provides additional parameters and improves the signal-to-noise ratio and sensitivity in crack detection compared to traditional ECT sensors.