Barometric pressure sensor based orientation measurement

• US 9,383,202 B2
• Filed: 03/12/2013
• Issued: 07/05/2016
• 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.
• Primary Examiner(s): Toatley, Gregory J
• Assistant Examiner(s): Alkafawi, Eman
• Application Number:
  US13/796,983
• Publication Number:
  US 20150153171A1
• Time in Patent Office: 1,211 Days
• Field of Search: 702/138, 702/150
• 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 having a display, the method comprising:

receiving readings from two pressure sensors mounted in the mobile device at substantially simultaneously the same time;

determining, by one or more processors, whether the difference in altitude between the two pressure sensors based on the received readings exceeds a threshold value;

determining that the mobile device is at a first angular orientation relative to the direction of gravity when the difference in altitude is above the threshold value;

determining that the mobile device is in a second orientation relative to the direction of gravity when the difference in altitude is below the threshold value, where the first angular orientation is closer to vertical than the second orientation relative to the direction of gravity; and

in response to determining that the mobile device is in the second orientation, switching the display between a portrait view and landscape view.

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 at substantially the same time;

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

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

determining the angular orientation of the mobile device using the Euler angle; and

selecting a portrait view or landscape view for a display based on the determined angular orientation.

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:

a display;

two pressure sensors;

one or more processors in communication with the pressure sensors; and

memory storing instructions executable by the one or more processors, wherein the instructions comprise;

receiving readings from the two pressure sensors at substantially the same time;

determining whether the difference in altitude between the two pressure sensors based on the received readings exceed a threshold value;

determining that the apparatus is at a first angular orientation relative to the direction of gravity when the difference in altitude is above the threshold value;

determining that the apparatus is in a second orientation relative to the direction of gravity when the difference is below the threshold value, where the first angular orientation is closer to vertical than the second orientation relative to the direction of gravity;

displaying data in portrait view on the display when the apparatus is determined to be at a first angular orientation; and

displaying data in landscape view on the display when the apparatus is determined to be in a second angular orientation.

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;

a navigation system;

at least three pressure sensors coupled to the housing;

one or more processors in communication with each of the pressure sensors; and

memory storing instructions executable by the one or more processors, wherein the instructions comprise;

receiving readings from each of the pressure sensors at substantially the same time;

determining differences in altitude among the pressure sensors based on the received readings;

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

determining the angular orientation of the housing of the apparatus using the Euler angle;

tracking data representative of at least one of turning, deceleration, position or velocity of the apparatus based on the determined angular orientation; and

providing the tracked data to the navigation system.

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.