BAROMETRIC PRESSURE SENSOR BASED ORIENTATION MEASUREMENT

• US 20150153171A1
• Filed: 03/12/2013
• Published: 06/04/2015
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Zhou, Shuchang, Chang, Edward Y.
• Granted Patent: US 9,383,202 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 5/06 by using barometric means
• CPC Class Codes: G06F 2200/1637 Sensing arrangement for detection of housing movement or orientation, e.g. for controlling scrolling or cursor movement on the display of an handheld computer

Abstract

Disclosed here are methods and systems that relate to determining an orientation of an object. The orientation of the object may be represented by an Euler angle which identifies a rotation of the object from a reference frame. The methods and systems may rely on readings collected from two or more barometric pressure sensors to estimate an altitude difference between the pressure sensors. The methods and systems may calculate the Euler angle based on the altitude difference.

Claims

1. A method of determining an orientation of a mobile device, the method comprising:

receiving readings from two pressure sensors mounted in the mobile device;

determining, by a processor, an altitude difference between the two pressure sensors based on the received readings;

comparing the altitude difference to a threshold value;

determining that the mobile device is in a first orientation when the altitude difference is above the threshold value, and

determining that the mobile device is in a second orientation when the altitude difference is below the threshold value.

2. The method of claim 1, wherein the two pressure sensors are barometric pressure sensors.

3. The method of claim 1, wherein the first orientation is a vertical position.

4. The method of claim 1, wherein the second orientation is a horizontal position.

5. A method of determining an orientation of a mobile device, comprising:

receiving readings from three pressure sensors mounted in the mobile device;

determining, by a processor, altitude differences among the three pressure sensors based on the received readings;

calculating an Euler angle based on the altitude differences, the Euler angle representing a rotation of a frame of the mobile device from a reference frame; and

determining the orientation of the mobile device using the Euler angle.

6. The method of claim 5, wherein the three pressure sensors are barometric pressure sensors.

7. The method of claim 5, wherein the three pressure sensors are mounted in the mobile device in a non-collinear manner.

8. The method of claim 5, wherein two of the three pressure sensors are mounted respectively on two axes of the frame of the mobile device, and a remaining pressure sensor is mounted at an origin of the frame of the mobile device.

9. An apparatus comprising:

two pressure sensors; and

a processor in communication with the pressure sensors, the processor configured to;

receive readings from the two pressure sensors;

determine an altitude difference between the two pressure sensors based on the received readings;

compare the altitude difference to a threshold value;

determine that the apparatus is in a first orientation when the altitude difference is above the threshold value; and

determine that the apparatus is in a second orientation when the altitude difference is below the threshold value.

10. The apparatus of claim 9, wherein the two pressure sensors are barometric pressure sensors.

11. The apparatus of claim 9, wherein the apparatus is a mobile device.

12. The apparatus of claim 9, wherein the first orientation is a vertical position.

13. The apparatus of claim 9, wherein the second orientation is a horizontal position.

14. An apparatus comprising:

a housing;

at least three pressure sensors coupled to the housing;

and

a processor in communication with each of the pressure sensors, the processor being configured to;

receive readings from each of the pressure sensors;

determine altitude differences among the pressure sensors based on the received readings;

calculate an Euler angle based on the altitude differences, the Euler angle representing a rotation of a frame of the apparatus from a reference frame; and

determine the orientation of the housing of the apparatus using the Euler angle.

15. The apparatus of claim 14, wherein the at least three pressure sensors are barometric pressure sensors.

16. The apparatus of claim 14, wherein the at least three pressure sensors are arranged in a non-collinear manner.

17. The apparatus of claim 14, wherein the apparatus is a mobile device.

18. The apparatus of claim 14, wherein the apparatus is a vehicle.

19. The apparatus of claim 14, wherein two of the at least three pressure sensors are mounted respectively on two axes of the frame of the apparatus, and a remaining pressure sensor is mounted at an origin of the frame of the apparatus.