Motion detection using pressure sensing

Patent metadata

Field	Value
Publication number	US-9945746-B2
Application number	US-201715461771-A
Country	US
Kind code	B2
Filing date	Mar 17, 2017
Priority date	Jul 3, 2014
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

According to an embodiment, a method of sensing motion includes receiving a first signal from a first pressure sensor and a second signal from a second pressure sensor, comparing the first signal and the second signal, and characterizing a motion based on the comparing.

First claim

What is claimed is:

1. A method of sensing motion, comprising:
generating a pressure signal with a pressure sensor;
band pass filtering the pressure signal; and
detecting a motion of the pressure sensor based on the filtered pressure signal.

2. The method of claim 1 , wherein band pass filtering comprises passing a frequency band between 0.5 Hz and 10 Hz.

3. The method of claim 1 , wherein band pass filtering passes a frequency band between 0.5 Hz and 50 Hz.

4. The method of claim 1 , wherein the pressure sensor is coupled to a structure that exhibits a reproducible motion and detecting the motion comprises detecting the reproducible motion.

5. The method of claim 1 , wherein the pressure sensor comprises a deflectable membrane formed adjacent to a sensing structure and configured to generate the pressure signal in response to deflections of the deflectable membrane.

6. The method of claim 5 , wherein the pressure sensor further comprises a pressure port coupled to the deflectable membrane, wherein the pressure port has a length extending away from the deflectable membrane that is at least three times greater than a longest dimension of the deflectable membrane.

7. A device, comprising:
a pressure sensor comprising a membrane having a planar surface, the pressure sensor being configured to generate a signal based on a deflection of the membrane; and
a motion detection circuit coupled to the pressure sensor, the motion detection circuit being configured to:
receive the signal from the pressure sensor;
filter the pressure signal to produce a filtered pressure signal; and
detect a motion of the pressure sensor based on the filtered pressure signal.

8. The device of claim 7 , wherein the pressure sensor comprises a sound port of a first length in a direction parallel to a normal to the planar surface, the first length being at least three times longer than a longest dimension of the membrane.

9. The device of claim 8 , wherein the sound port is filled with foam.

10. The device of claim 8 , wherein the sound port comprises a guide grid.

11. The device of claim 8 , wherein the first length is at least ten times longer than the longest dimension of the membrane.

12. The device of claim 7 , wherein the motion detection circuit comprises a band pass filter configured to produce the filtered pressure signal, the band pass filter being configured to pass a frequency band between 0.5 Hz and 10 Hz.

13. The device of claim 12 , wherein the band pass filter is configured to pass a frequency band between 0.5 Hz and 50 Hz.

14. The device of claim 7 , further comprising a structure configured to exhibit a reproducible motion, and wherein the motion detection circuit is configured to detect the reproducible motion based on the filtered pressure signal.

15. A device, comprising:
a pressure sensor configured to generate a pressure signal;
a band pass filter configured to filter the pressure signal to produce a filtered pressure signal, the band pass filter being configured to pass frequencies between 0.5 Hz and 10 Hz; and
a signal processing circuit configured to generate a motion value based on the filtered pressure signal, the motion value being indicative of a motion of the device.

16. The device of claim 15 , wherein the device comprises at least one of a lever or a hinged lid.

17. The device of claim 15 , wherein the band pass filter is configured to pass frequencies between 0.5 Hz and 50 Hz.

18. The device of claim 15 , wherein the pressure sensor comprises a membrane having a planar surface and a sound port having a first length and extending in a direction parallel to a normal to the planar surface, the first length being at least three times longer than a longest dimension of the membrane.

19. The device of claim 18 , wherein the sound port is filled with foam.

20. The device of claim 18 , wherein the sound port comprises a guide grid.

Assignees

• Infineon Technologies Ag

Inventors

• Wiesbauer Andreas
• Mandl Christian
• Kopetz Andreas
• Helm Roland

Classifications

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R23/00

  Transducers other than those covered by groups H04R9/00 - H04R21/00 {(diaphragms for transducers of the distributed-mode type H04R7/045)} · CPC title

• G01L15/00 Primary

  Devices or apparatus for measuring two or more fluid pressure values simultaneously · CPC title

• G01L13/025 Primary

  using diaphragms · CPC title

• H04R19/04

  Microphones (H04R19/01 takes precedence) · CPC title