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

• US 10,060,764 B2
• Filed: 09/22/2015
• Issued: 08/28/2018
• Est. Priority Date: 09/22/2014
• Status: Active Grant

• Current Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Original Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Inventors: Lehmann, Soren, Schirling, Andreas
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): Rhodes-Vivour, Temilade
• Application Number:
  US15/505,386
• Publication Number:
  US 20170268907A1
• Time in Patent Office: 1,071 Days
• CPC Class Codes: G01C 1/00 Measuring angles
• CPC Class Codes: G01D 5/20 by varying inductance, e.g. by a movable armature
• CPC Class Codes: G01D 5/2291 Linear or rotary variable differential transformers (LVDTs/RVDTs) having a single primary coil and two secondary coils
• CPC Class Codes: G06F 2101/00 Indexing scheme relating to the type of digital function generated
• CPC Class Codes: H01L 21/00 Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
• CPC Class Codes: H01L 2221/00 Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof covered by H01L21/00

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.

Claims

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.