Inductive position sensor with frequency converter and Goertzel filter for analyzing signals

Patent metadata

Field	Value
Publication number	US-10060764-B2
Application number	US-201515505386-A
Country	US
Kind code	B2
Filing date	Sep 22, 2015
Priority date	Sep 22, 2014
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A position sensor connected to first and second electric signal sources to output a first electric signal with a first frequency and a second electric signal with a second frequency. The position sensor includes: a primary coil generating a magnetic alternating field with the first frequency; a first and a second secondary coil, the first and second secondary coils each magnetically coupled to the primary coil by the position transmitter, and third and fourth electric signals induced in the first and second secondary coils respectively by the generated magnetic alternating field; a frequency converter converts the third and fourth electric signals into respective first and second intermediate frequency signals, the frequency converter connectable to the second electric signal source. A Goertzel filter bank demodulates the first intermediate frequency signal to obtain a first demodulated signal and demodulates the second intermediate frequency signal to obtain a second demodulated signal.

First claim

The invention claimed is:

1. A position sensor for detecting a position of a position transmitter, wherein the position sensor is connected to a first electric signal source in order to output a first electric signal with a first frequency and to a second electric signal source in order to output a second electric signal with a second frequency, comprising:
a primary coil for generating an alternating magnetic field with the first frequency;
a first secondary coil and a second secondary coil, wherein the first secondary coil and the second secondary coil are each magnetically coupled to the primary coil by the position transmitter, and wherein a third electric signal is induced in the first secondary coil and a fourth electric signal is induced in the second secondary coil by the generated alternating magnetic field;
a frequency converter for converting the third electric signal into a first intermediate frequency signal and for converting the fourth electric signal into a second intermediate frequency signal, wherein the frequency converter is connectable to the second electric signal source; and
a Goertzel filter bank for the demodulation of the first intermediate frequency signal in order to obtain a first demodulated signal, and for the demodulation of the second intermediate frequency signal in order to obtain a second demodulated signal.

2. The position sensor as claimed in claim 1 , further comprising a processor for determining the position of the position transmitter as a function of the first demodulated signal or of the second demodulated signal.

3. The position sensor as claimed in claim 2 , wherein an analog-digital converter is connected upstream of the Goertzel filter bank.

4. The position sensor as claimed in claim 1 , wherein an analog-digital converter is connected upstream of the Goertzel filter bank.

5. The position sensor as claimed in claim 1 , wherein a device for signal windowing is connected upstream of the Goertzel filter bank.

6. The position sensor as claimed in claim 1 , wherein the Goertzel filter bank comprises a first Goertzel filter for the demodulation of the first intermediate frequency signal and a second Goertzel filter for the demodulation of the second intermediate frequency signal.

7. The position sensor as claimed in claim 1 , further comprising a signal output for outputting the first demodulated signal or the second demodulated signal.

8. The position sensor as claimed in claim 1 , wherein a device for linearizing the first demodulated signal or the second demodulated signal is connected downstream from the Goertzel filter bank.

9. The position sensor as claimed in claim 1 , wherein a bandpass filter is connected downstream from the frequency converter.

10. The position sensor as claimed in claim 1 , wherein an amplifier is connected downstream from the frequency converter.

11. The position sensor as claimed in claim 1 , wherein the frequency converter comprises a first mixer for mixing the third electric signal with the second electric signal, and a second mixer for mixing the fourth electric signal with the second electric signal.

12. The position sensor as claimed in claim 1 , further comprising the first electric signal source and the second electric signal source.

13. The position sensor as claimed in claim 12 , wherein an amplifier is connected downstream from the first electric signal source or the second electric signal source.

14. The position sensor as claimed in claim 13 , further comprising a frequency generator for generating a further electric signal with a third frequency, wherein the first electric signal source is embodied to generate the first electric signal on the basis of thefurther electric signal, and wherein the second electric signal source is embodied to generate the second electric signal on the basis of the further electric signal.

15. The position sensor as claimed in claim 12 , further comprising a frequency generator for generating a further electric signal with a third frequency, wherein the first electric signal source is embodied to generate the first electric signal on the basis of the further electric signal, and wherein the second electric signal source is embodied to generate the second electric signal on the basis of the further electric signal.

16. The position sensor as claimed in claim 15 , wherein the first frequency or the second frequency is an integral multiple of the third frequency, or wherein the third frequency is an integral multiple of the first frequency or of the second frequency.

17. The position sensor as claimed in claim 16 , wherein the first electric signal source comprises a synthesizer for generating the first electric signal with the first frequency on the basis of the further electric signal, or wherein the second electric signal source comprises a synthesizer for generating the second electric signal with the second frequency on the basis of the further electric signal.

18. The position sensor as claimed in claim 15 , wherein the first electric signal source comprises a synthesizer for generating the first electric signal with the first frequency on the basis of the further electric signal, or wherein the second electric signal source comprises a synthesizer for generating the second electric signal with the second frequency on the basis of the further electric signal.

Assignees

• Continental Teves Ag & Co Ohg

Inventors

• Lehmann Sören
• Schirling Andreas

Classifications

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• G01C1/00

  Measuring angles · CPC title

• G01D5/2291 Primary

  Linear or rotary variable differential transformers (LVDTs/RVDTs) having a single primary coil and two secondary coils · CPC title

• G01D5/20 Primary

  by varying inductance, e.g. by a movable armature · CPC title

• G06F2101/00

  Indexing scheme relating to the type of digital function generated · CPC title