Impedance measurement device and method based on random demodulator

Abstract

The invention relates to an impedance measurement device and method based on a random demodulator. The impedance measurement method is characterized by comprising the following process: applying sinusoidal voltage excitation to an impedance element to be measured; converting a current signal passing through the impedance element into a voltage signal through a current-voltage conversion circuit; after the voltage signal is randomly modulated through a two-path switch and passes through a low-pass filter, carrying out low-speed sampling by an A / D (Analog / Digital) converter to obtain a low-speed sampling sequence; and carrying out signal reconstruction on an upper computer by using the low-speed sampling sequence to obtain power spectrum information of the voltage signal output by the current-voltage conversion circuit, so as to obtain a signal amplitude, a phase and an element resistance value and realize the impedance measurement based on the random demodulator. With the adoption of the method provided by the invention, the impedance measurement is realized when ADC (Analog to Digital Converter) sampling frequency is lower than the frequency of the sampled signal; a multiplying unit is not needed, and only low-power-consumption devices including the electronic switch, the low-speed analog-digital converter and the like are needed; and the impedance measurement device and method have the characteristics of low cost, low power consumption, less resource consumption and simplicity in realization, and have a wide application prospect.

Description

Technical field [0001] An impedance measurement device and method based on a random demodulator belong to the field of distributed parameter measurement. Background technique [0002] Impedance is an inherent property of components and materials, and it is also a basic parameter associated with circuits. Impedance measurement is not only an important content in the field of electrical measurement, but also through the measurement of impedance parameters, it is often possible to indirectly achieve rapid measurement of many other physical quantities; such as the displacement, temperature, pressure, speed, flow and other sensors commonly used in engineering. The signals are mostly impedance parameters such as capacitance, resistance or inductance. [0003] With the rapid development of new detection technology, impedance measurement technology has been rapidly expanded to biomedicine, electrochemistry, power control, large-scale integrated circuit manufacturing, space technology and ...

AI Technical Summary

Problems solved by technology

[0014] Among the relevant patents that have been applied for, Zheng Shilian et al. disclosed a method for judging the failure of random demodulator compression sampling reconstruction in 2013 (public number: CN103248368A), and Fu Ning et al. disclosed a method for obtaining random demodulation hardware The method of the perception matrix of the system (public number: CN103344849A), has not seen the hardware optimization of the random demodulator and its application in impedance measurement

Images