Low accuracy positional data by detecting improbable samples

• US 8,981,995 B2
• Filed: 06/03/2011
• Issued: 03/17/2015
• Est. Priority Date: 06/03/2011
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Schlesinger, Benny, Kuper, Vadim
• Primary Examiner(s): Phan, Dao
• Application Number:
  US13/152,299
• Publication Number:
  US 20120306699A1
• Time in Patent Office: 1,383 Days
• Field of Search: 342/451, 342/457, 342/463, 342/465, 455/456.1, 455/456.6
• US Class Current: 342/451
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

An embodiment of the invention provides a method of determining a location of a mobile target that processes locations for the target provided by a wireless location technology tracker system to determine if the locations are outliers, discards locations that are determined to be outliers, and uses locations determined not to be outliers as locations for the target.

Claims

1. A method of determining a location of a mobile target, the method comprising:

receiving data provided by a wireless location technology (WILOT) defining a plurality of locations responsive to locations of the target at different times;

determining whether a given location of the plurality of locations is an outlier location;

if the given location is determined to be an outlier, receiving data defining an additional location for the target and determining if the outlier location is corroborated by the additional location; and

if corroborated, using the outlier location as a location for the target.

2. A method according to claim 1, wherein if the outlier is not corroborated, comprising determining whether the outlier is compatible with features of the target.

3. A method according to claim 2, wherein if the outlier is compatible with features of the target comprising using the outlier to provide a location for the target.

4. A method according to claim 2 and comprising determining if the outlier is compatible with features of the environment, and only if compatible with features of the environment, using the outlier to provide a location for the target.

5. A method according to claim 1 wherein determining whether the given location is an outlier comprises calculating a moving average for a velocity characteristic of the target responsive to the plurality of locations and using the moving average of the velocity to determine if the given location is an outlier.

6. A method according to claim 5 and determining a variance for the moving average velocity and using the variance to determine if the given location is an outlier.

7. A method according to claim 6 and using the moving average velocity and its variance to determine an expected location for the given location.

8. A method according to claim 7 and using the moving average velocity and its variance to determine an expected region of uncertainty (ROU) for the expected location.

9. A method according to claim 8 and determining that the given location is an outlier if it is not consistent with the expected location and expected ROU.

10. A method according to claim 1 wherein determining whether the given location is an outlier comprises calculating a moving average for an acceleration of the target responsive to the plurality of locations, and using the moving average of the acceleration to determine if the given location is an outlier.

11. A method according to claim 10 and determining a variance for the moving average acceleration and using the variance to determine if the given location is an outlier.

12. A method according to claim 11 and determining an expected location for the given location responsive to the moving average acceleration and its variance.

13. A method according to claim 12 and using the moving average velocity and its variance to determine an expected region of uncertainty (ROU) for the expected location determined responsive to the moving average acceleration and its variance.

14. A method according to claim 13 and determining that the given location is an outlier if it is not consistent with the expected location and expected ROU determined responsive to the moving average acceleration and its variance.

15. Apparatus for determining a location of a mobile target, the apparatus comprising:

a wireless location technology (WILOT) tracker that provides a plurality of locations of the target; and

a processor that;

determines whether a given location of the plurality of locations is an outlier location;

receives data defining an additional location for the target if the given location is determined to be an outlier;

determines if the outlier location is corroborated by the additional location; and

if corroborated, uses the outlier location as a location for the target.

16. Apparatus according to claim 15 wherein the processor:

generates moving averages for a velocity that characterizes motion of the target responsive to the locations;

uses the moving averages to determine whether or not a given location provided by the WILOT tracker is an outlier; and

uses the given location as a location for the target if it is determined not to be an outlier.

17. Apparatus according to claim 16 wherein the processor determines a variance for the moving average velocity responsive to the locations.

18. Apparatus according to claim 17 wherein the processor uses the moving average velocity and its variance to determine an expected region of uncertainty (ROU) for the location.

19. Apparatus according to claim 18 wherein the processor determines that the gin location is an outlier if it is not consistent with the location and expected ROU.

20. Apparatus according to claim 16 wherein the processor generates moving averages of an acceleration that characterizes motion of the target responsive to the locations provided by the WILOT tracker and uses the moving average acceleration to determine if the given location is an outlier.