Locating a mobile computing device in an indoor environment

Patent metadata

Field	Value
Publication number	US-9310462-B2
Application number	US-201213606008-A
Country	US
Kind code	B2
Filing date	Sep 7, 2012
Priority date	Sep 7, 2012
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

Inferring location of a mobile computing device in an indoor environment and crowdsourcing radio frequency data are described herein. A location of the mobile computing device in the indoor environment is inferred based upon known physical constraints of the indoor environment and data from an inertial sensor of the mobile computing device, wherein an initial location in the indoor environment of the mobile computing device is unknown, a heading offset of the mobile computing device is arbitrary, and wherein a placement of the mobile computing device on a user is arbitrary.

First claim

What is claimed is:

1. A method, comprising:
receiving data pertaining to a mobile computing device that comprises an inertial sensor, the data comprising:
an initial reading from the inertial sensor in the mobile computing device, the initial reading obtained when the mobile computing device is at an initial location in an indoor environment, wherein the initial location is unknown; and
a plurality of readings from the inertial sensor, the plurality of readings obtained subsequent in time from when the initial reading was obtained, the plurality of readings from the inertial sensor obtained over a range of time as the mobile computing device transits along a path in the indoor environment beginning at the initial location; and

inferring at least one location along the path of the mobile computing device in the indoor environment based at least in part upon the initial reading and the plurality of readings, wherein inferring of the at least one location of the mobile computing device in the indoor environment comprises inferring a length of a stride of a user of the mobile computing device based upon the initial reading and the plurality of readings.

2. The method of claim 1 , wherein an orientation of the mobile computing device relative to a direction of motion of the mobile computing device when transiting along the path is arbitrary, and wherein inferring the at least one location along the path of the mobile computing device further comprises inferring a heading offset of the mobile computing device, the heading offset being a difference in the orientation of the mobile computing device relative to the direction of motion of the mobile computing device.

3. The method of claim 1 , wherein a position of the mobile computing device relative to a body of a user of the mobile computing device is arbitrary.

4. The method of claim 1 , wherein the at least one location that is inferred is the initial location of the wireless computing device.

5. The method of claim 1 , wherein the at least one location is a current location of the wireless computing device in the indoor environment.

6. The method of claim 1 , further comprising inferring the path of the mobile computing device in the indoor environment by way of backpropagation, wherein the initial location is inferred based at least in part upon the inferring of the at least one location.

7. The method of claim 1 , wherein the inferring of the at least one location of the mobile computing device in the indoor environment further comprises:
computing a shape of the path of the mobile computing device in the indoor environment;
comparing the shape of the path of the mobile computing device in the indoor environment with path boundaries specified in a map of the indoor environment; and
inferring the at least one location of the mobile computing device in the indoor environment based at least in part upon the comparing of the shape of the path of the mobile computing device in the indoor environment with the path boundaries specified in the map of the indoor environment.

8. The method of claim 1 , wherein the readings are obtained over the range of time, and wherein the inferring is undertaken as the data is received.

9. The method of claim 1 , wherein the inertial sensor is one of an accelerometer, a compass, or a gyroscope.

10. The method of claim 1 , further comprising receiving signal strength values of respective wireless signals received at the mobile computing device over the range of time, the respective wireless signals received at the mobile computing device from wireless signal transmitters that are external to the mobile computing device, and wherein the method further comprises assigning at least one signal strength value to the at least one location based at least in part upon the inferring of the at least one location of the mobile computing device in the indoor environment.

11. The method of claim 1 being executed by the mobile computing device.

12. The method of claim 1 , wherein the inferring of the at least one location of the mobile computing device in the indoor environment further comprises computing probability distributions of respective locations of the mobile computing device in the indoor environment as the mobile computing device transits along the path.

13. The method of claim 12 , wherein the computing of the probability distributions of the respective locations of the mobile computing device in the indoor environment as the mobile computing device transits along the path comprises utilizing multi-dimensional particle filtering comprising a plurality of dimensions, wherein the plurality of dimensions comprises dimensions corresponding to physical location, a dimension corresponding to a stride length of a user of the mobile computing device, and a dimension corresponding to a heading offset of the mobile computing device.

14. A system, comprising:
a processor; and
memory that comprises instructions that, when executed by the processor, cause the processor to perform acts comprising:
receiving data generated by at least one inertial sensor in a mobile computing device, the mobile computing device residing in an indoor environment, and wherein the data comprises:
first data generated by the at least one inertial sensor when the mobile computing device is at an initial unknown location in the indoor environment, the initial unknown location being an arbitrary location in the indoor environment, and wherein the initial unknown location is indeterminable based solely upon the first data; and
second data generated by the at least one inertial sensor subsequent to the mobile computing device being at the initial unknown location in the indoor environment, the second data generated by the at least one inertial sensor during transit of the mobile computing device from the initial unknown location along a path;

estimating a length of a stride of a user of the mobile computing device based upon the second data generated by the at least one inertial sensor; and
inferring a geographic location of the initial unknown location of the mobile computing device in the indoor environment based at least in part upon the first data and the estimated length of the stride of the user.

15. The system of claim 14 , the acts further comprising:
receiving a signal strength value for a signal transmitted by a wireless access point and received at the mobile computing device at a time corresponding to the first data; and
assigning the signal strength value to the geographic location subsequent to the geographic location of the initial unknown geographic location being inferred.

16. The system of claim 14 , wherein inferring a geographic location of the initial unknown location of the mobile computing device in the indoor environment comprises inferring the geographic location of the initial unknown location of the mobile computing device based upon a comparison between the path of the mobile computing device and known physical constraints of the indoor environment.

17. The system of claim 14 , the acts further comprising:
inferring a current geographic location of the mobile computing device in the indoor environment based at least in part upon the first data and the second data; and
causing a location-based alert to be presented to a user of the mobile computing device based at least in part upon the inferred current geographic location of the mobile computing device.

18. A computer-readable data storage device comprising instructions that, when executed by a processor, cause the processor to perf

Assignees

• Chintalapudi Krishna
• Padmanabhan Venkata N
• Rai Anshul
• Sen Rijurekha
• Sidhu Gursharan Singh
• Microsoft Technology Licensing Llc

Inventors

• Chintalapudi Krishna
• Padmanabhan Venkata N
• Rai Anshul
• Sen Rijurekha
• Sidhu Gursharan Singh

Classifications

• G01C21/1656

  with passive imaging devices, e.g. cameras · CPC title

• G01S5/0264

  at least one of the systems being a non-radio wave positioning system · CPC title

• G01S5/02526 Primary

  using non-dedicated equipment, e.g. user equipment or crowd-sourcing · CPC title

• H04W4/027

  using movement velocity, acceleration information · CPC title

• G01C22/006

  Pedometers · CPC title