Resistance-capacitance Decoupling Soft-sensing Based on Amplitude and Phase Detection

摘要

The problem of Resistance-capacitance (RC) network parameter decoupling estimation is discussed with the background of conductivity measurement. Sinusoidal signal is adopted to excite the RC network, and the response is also the sinusoidal signal which has the same frequency as excitation, but amplitude and phase change. By obtaining the amplitude and phase characteristics of RC network, the value of RC network parameter can be estimated. To eliminate the effect of measurement uncertainty, the multi-sampling of response signal can be used to fit out the function form of response based on the nonlinear least squares method, and then the amplitude ratio and phase difference between response and excitation can be obtained. To ensure the real-time of measurement, gradient method is used to optimization calculation. High measurement accuracy and less iterative times can be achieved, and experimental results show the effectiveness of the proposed method.