Pedestrian sensor assistance in a mobile device during typical device motions

• US 10,041,800 B2
• Filed: 09/23/2016
• Issued: 08/07/2018
• Est. Priority Date: 09/23/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Morrison, William, Sun, Ming, Luo, Ning, Czompo, Joseph, Werner, Benjamin
• Primary Examiner(s): Sweeney, Brian P
• Application Number:
  US15/275,006
• Publication Number:
  US 20180087904A1
• Time in Patent Office: 683 Days
• Field of Search: 701534
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01C 21/1656 with passive imaging devices, e.g. cameras
• CPC Class Codes: G01C 21/183 Compensation of inertial measurements, e.g. for temperature effects
• CPC Class Codes: G01C 22/006 Pedometers
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices

Abstract

Techniques provided herein are directed toward resolving a direction of travel of a mobile device based on MEMS sensor data by identifying a type of motion the mobile device is subject to and offsetting vertical acceleration data with horizontal acceleration data by a predetermined time offset based on the identified type of motion. The offset vertical and horizontal acceleration data can then be used to resolve, with an increased accuracy, a direction of travel of the mobile device.

Claims

1. A mobile device comprising:

one or more micro electromechanical system (MEMS)-based sensors configured to provide MEMS sensor data indicative of motion of a user, the MEMS sensor data including vertical acceleration data and horizontal acceleration data; and

a processing unit communicatively coupled with the one or more MEMS-based sensors and configured to;

obtain the MEMS sensor data from the one or more MEMS-based sensors;

use the vertical acceleration data and the horizontal acceleration data of the MEMS sensor data to;

determine an estimated direction of travel, and

match the motion of the user with an identified type of motion;

offset the vertical acceleration data from the horizontal acceleration data by a predetermined phase offset for the identified type of motion; and

use the offset vertical and horizontal acceleration data to determine a corrected direction for the estimated direction of travel.

2. The mobile device of claim 1, wherein the processing unit is further configured to determine a boosted vector based on the offset of the vertical acceleration data from the horizontal acceleration data.

3. The mobile device of claim 2, wherein the processing unit is configured to use the offset vertical and horizontal acceleration data to determine the corrected direction of the estimated direction of travel by performing a dot product of the boosted vector and a vector representing the estimated direction of travel.

4. The mobile device of claim 3, wherein the processing unit is further configured to transform the MEMS sensor data such that the vector representing the estimated direction of travel and the boosted vector are in a horizontal plane defined relative to the earth'"'"'s surface.

5. The mobile device of claim 2, wherein the processing unit is configured to determine the boosted vector by determining horizontal scalars, where each horizontal scalar is a sum of a multiplication of a vertical component of a vector representing the estimated direction of travel and a corresponding horizontal component of the vector representing the estimated direction of travel.

6. The mobile device of claim 1, wherein the processing unit is configured to determine the type of motion by selecting, based on the MEMS sensor data, the determined type of motion from a plurality of types of motion.

7. A method of providing pedestrian sensor assistance in a mobile device, the method executed by a processing unit and comprising:

obtaining microelectromechanical system (MEMS) sensor data from one or more MEMS-based sensors, the MEMS sensor data including vertical acceleration data and horizontal acceleration data;

using the vertical acceleration data and the horizontal acceleration data of the MEMS sensor data to;

determine an estimated direction of travel, and

match the motion of the user with an identified type of motion;

offsetting the vertical acceleration data from the horizontal acceleration data by a predetermined phase offset for the identified type of motion; and

using the offset vertical and horizontal acceleration data to determine a corrected direction for the estimated direction of travel.

8. The method of claim 7, further comprising determining a boosted vector based on the offset of the vertical acceleration data from the horizontal acceleration data.

9. The method of claim 8, further comprising using the offset vertical and horizontal acceleration data to determine the corrected direction of the estimated direction of travel by performing a dot product of the boosted vector and a vector representing the estimated direction of travel.

10. The method of claim 9, further comprising transforming the MEMS sensor data such that the vector representing the estimated direction of travel and the boosted vector are in a horizontal plane defined relative to the earth'"'"'s surface.

11. The method of claim 8, further comprising determining the boosted vector by determining horizontal scalars, where each horizontal scalar is a sum of a multiplication of a vertical component of a vector representing the estimated direction of travel and a corresponding horizontal component of the vector representing the estimated direction of travel.

12. The method of claim 7, further comprising determining the type of motion by selecting, based on the MEMS sensor data, the determined type of motion from a plurality of types of motion.

13. An apparatus comprising:

means for obtaining motion data including vertical acceleration data and horizontal acceleration data;

means for using the vertical acceleration data and the horizontal acceleration data of the motion data to;

determine an estimated direction of travel, and

match the motion of the user with an identified type of motion;

means for offsetting the vertical acceleration data from the horizontal acceleration data by a predetermined phase offset for the identified type of motion; and

means for using the offset vertical and horizontal acceleration data to determine a corrected direction for the estimated direction of travel.

14. The apparatus of claim 13, further comprising means for determining a boosted vector based on the offset of the vertical acceleration data from the horizontal acceleration data.

15. The apparatus of claim 14, further comprising means for using the offset vertical and horizontal acceleration data to determine the corrected direction of the estimated direction of travel by performing a dot product of the boosted vector and a vector representing the estimated direction of travel.

16. The apparatus of claim 15, further comprising means for transforming the motion data such that the vector representing the estimated direction of travel and the boosted vector are in a horizontal plane defined relative to the earth'"'"'s surface.

17. The apparatus of claim 14, further comprising means for determining the boosted vector by determining horizontal scalars, where each horizontal scalar is a sum of a multiplication of a vertical component of a vector representing the estimated direction of travel and a corresponding horizontal component of the vector representing the estimated direction of travel.

18. The apparatus of claim 13, further comprising means for determining the type of motion by selecting, based on the motion data, the determined type of motion from a plurality of types of motion.

19. A non-transitory computer-readable medium having instructions embedded thereon for providing pedestrian sensor assistance in a mobile device, the instructions including computer code which, when executed by one or more devices, cause the one or more devices to:

obtain microelectromechanical system (MEMS) sensor data from one or more MEMS-based sensors, the MEMS sensor data including vertical acceleration data and horizontal acceleration data;

use the vertical acceleration data and the horizontal acceleration data of the MEMS sensor data to;

determine an estimated direction of travel, and

match the motion of the user with an identified type of motion;

offset the vertical acceleration data from the horizontal acceleration data by a predetermined phase offset for the identified type of motion; and

use the offset vertical and horizontal acceleration data to determine a corrected direction for the estimated direction of travel.

20. The non-transitory computer-readable medium of claim 19, wherein the instructions further comprise computer code for determining a boosted vector based on the offset of the vertical acceleration data from the horizontal acceleration data.

21. The non-transitory computer-readable medium of claim 20, wherein the instructions further comprise computer code for using the offset vertical and horizontal acceleration data to determine the corrected direction of the estimated direction of travel by performing a dot product of the boosted vector and a vector representing the estimated direction of travel.

22. The non-transitory computer-readable medium of claim 21, wherein the instructions further comprise computer code for transforming the MEMS sensor data such that the vector representing the estimated direction of travel and the boosted vector are in a horizontal plane defined relative to the earth'"'"'s surface.

23. The non-transitory computer-readable medium of claim 20, wherein the instructions further comprise computer code for determining the boosted vector by determining horizontal scalars, where each horizontal scalar is a sum of a multiplication of a vertical component of a vector representing the estimated direction of travel and a corresponding horizontal component of the vector representing the estimated direction of travel.

24. The non-transitory computer-readable medium of claim 19, wherein the instructions further comprise computer code for determining the type of motion by selecting, based on the MEMS sensor data, the determined type of motion from a plurality of types of motion.