METHOD FOR MEASURING THE IMPEDANCE OF ELECTRICAL COMPONENTS

1 . A method for determining, at multiple intervals and thus repeatedly, an electrical signal characteristic of a magnitude of and/or a change in an impedance which changes under influence of a magnetic, electric, and/or electromagnetic field, wherein the magnetic, electric, and/or electromagnetic field for its part changes due to an object approaching the impedance, the method comprising:

performing measurements at least in one group of measurement intervals, which has one or more consecutive measurement intervals, and at least one compensation interval positioned chronologically before the at least one group of measurement intervals or before each group of measurement intervals;

per measurement interval:

applying a sinusoidal excitation voltage to the impedance; and

inducing a measuring current in the impedance as a result of the sinusoidal excitation voltage;

using the measurement current of a measurement interval as a compensation current for at least one subsequent measurement interval by subtracting a compensation current in the at least one subsequent measurement interval from the measurement current of the measurement interval to generate an analog evaluation current signal;

using the generated analog evaluation current as a signal characteristic of a magnitude and/or a change in the impedance due to an object approaching the impedance.

2 . The method according to claim 1 , further comprising, upon determining the compensation current, generating a compensation signal during the at least one measuring interval, by a signal generating unit to be subtracted from the measuring current of the at least one measuring interval.

3 . The method according to claim 1 , further comprising amplifying the analog evaluation current signal, wherein the amplified analog evaluation current signal is a signal characteristic of the magnitude and/or the change in impedance.

4 . The method according to claim 1 , further comprising:

providing a first compensation current for an initial state;

performing, as a part of the one group of measurement intervals, a first set of measurement intervals chronologically preceding a first compensation interval; and

generating the compensation current during the first set of measurement intervals based on the first compensation current.

5 . The method according to claim 1 , wherein generating the compensation current further includes

applying a neural network of any type and any structure and/or

applying a Hidden Markov Model and/or

applying a Petri net and/or automatic learning for generating knowledge from past and previous experiences, such as machine learning, deep learning and/or a processing of predictors, i.e., predictive variables from events registered in the past.

6 . The method according to claim 1 , further comprising:

converting, by an analog-to-digital converter, the analog evaluation current signal;

demodulating the converted analog evaluation current signal, by an I-Q demodulation;

determining an I signal component and/or a Q signal component from the demodulated evaluation current signal; and

using the I signal component and/or the Q signal component as the signal characteristic of the magnitude and/or the change in impedance.

7 . The method according to claim 6 , further comprising digitally generating parameters of the I-Q demodulation in the at least one compensation interval.

8 . The method according to claim 1 , further comprising selecting at least one of a resistive, an inductive and a capacitive impedance as the impedance, wherein the capacitive impedance is designed as a capacitor with dielectric or as an electrode surface.

9 . A method for determining, at multiple intervals and thus repeatedly, an electrical signal characteristic of a magnitude of and/or a change in an impedance which changes under influence of a magnetic, electric and/or electromagnetic field, wherein the magnetic, electric and/or electromagnetic field for its part changes due to an object approaching the impedance, comprising:

per interval

applying, a sinusoidal excitation voltage to the impedance;

inducing a measuring current in the impedance as a result of the excitation voltage;

feeding a difference between the measuring current and a compensation current to an input of an analog or digital integrator, an_output of which supplies the compensation current after digital-to-analog conversion, if necessary; and

forming a signal characteristic of the magnitude and/or change in impedance based on the output of the integrator.

10 . The method according to claim 9 , further comprising:

amplifying a difference signal from a difference between the measuring current and the compensation current;

performing an analog-to-digital conversion on the amplified difference signal to generate a converted difference signal;

feeding the converted difference signal to a digital I-Q demodulator;

feeding I and Q signal components of the digital I-Q demodulator to an input of a digital integrator;

integrating the I and Q signal components over time to form the compensation current;

modulating an output of the I-Q demodulator a digital I-Q modulator; and

applying an output of the digital I-Q modulator to a digital-to-analog converter, thereby outputting the compensation current.

11 . A method for determining, at multiple intervals and thus repeatedly, an electrical signal characteristic of a_magnitude of and/or a change in an impedance which changes under influence of a magnetic, electric and/or electromagnetic field, wherein the magnetic, and/or electromagnetic field for its part changes due to an object approaching the impedance, comprising:

per interval

applying a sinusoidal excitation voltage to the impedance;

inducing a measuring current in the impedance as a result of the sinusoidal excitation voltage;

applying a compensation voltage that is 180° out of phase with the sinusoidal excitation voltage to a reference impedance of known magnitude;

inducing a compensation current in the reference impedance as a result of the compensation voltage,

feeding a difference signal between the measuring current and the compensation current, possibly after amplification, to an input of an analog or digital integrator;

providing a magnitude of the compensation current possibly after digital-to-analog conversion based on the integrated difference signal;

generating the compensation voltage; and

outputting, from the integrator, a signal characteristic of the magnitude and/or the change in impedance.

12 . The method according to claim 11 , wherein applying the compensation voltage to the reference impedance further comprises selecting from a plurality of reference impedances each having a known magnitude, applying the reference voltage to one of the selected reference impedances, and supplying the compensation current as a result of applying the reference voltage to the selected reference impedance.

13 . The method according to claim 11 , wherein a magnitude of the reference impedance is variably adjustable and is varied by a controller having an input and an output, the input of the controller receiving the signal at the output of the integrator, and the output of the controller providing the signal characteristic of the magnitude and/or variation of the impedance.

14 . The method according to claim 11 , wherein the difference signal between the measuring current and the compensation current is subjected to an analog-to-digital conversion to generate a converted difference signal, and the converted difference signal is then fed to a digital I-Q demodulator, wherein I and Q signal components of the converted difference signal generated by the digital I-Q demodulator are fed to an input of a digital integrator, and further wherein, to form the compensation voltage, the I and Q signal components integrated over time are modulated in a digital I-Q modulator, the output of the digital I-Q modulator being connected to a digital-to-analog converter that outputs the compensation current.

15 . The method according to claim 11 , wherein the difference signal between the measuring current and the compensation current is subjected to an analog-to-digital conversion to generate a converted difference signal, and the converted difference signal is then fed to a digital I-Q demodulator, wherein I and Q signal components of the converted difference signal generated by the digital I-Q demodulator are fed to an input of a digital integrator, and further wherein, to form the compensation voltage, the I and Q signal components integrated overtime are modulated in a digital I-Q modulator whose output is connected to a digital-to-analog converter that outputs the compensation current, and I and Q portions of the reference impedance are adjusted according to control specifications for I and Q portions in a superimposed control loop with digital control in dependence on the I and Q signal components integrated over time output by the digital integrator.

16 . A method for determining, at multiple intervals and thus repeatedly, an electrical signal characteristic of a magnitude of and/or a change in an impedance which changes under influence of a magnetic, electric and/or electromagnetic field, wherein the magnetic, and/or electromagnetic field for its part changes due to an object approaching the impedance, the method comprising:

per interval

applying a sinusoidal excitation voltage to the impedance;

inducing a measuring current in the impedance as a result of applying the excitation voltage;

calculating a compensation current based on the measuring current or a variable derived therefrom by:

a neural network of any type and any structure and/or

a Hidden Markov Model and/or

a Petri net and/or automatic learning of any kind for generating knowledge from past and previous experiences, such as machine learning, deep learning and/or processing of predictive variables from events registered in the past, and

a difference between the measuring current and the compensation current forms a signal characteristic of a magnitude and/or change in impedance.