LOCATING A MOBILE COMPUTING DEVICE IN AN INDOOR ENVIRONMENT

• US 20140073345A1
• Filed: 09/07/2012
• Published: 03/13/2014
• Est. Priority Date: 09/07/2012
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Padmanabhan, Venkata N., Rai, Anshul, Sidhu, Gursharan Singh, Chintalapudi, Krishna, Sen, Rijurekha
• Granted Patent: US 9,310,462 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01C 21/1656 with passive imaging devices, e.g. cameras
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01C 22/006 Pedometers
• CPC Class Codes: G01S 5/02526 using non-dedicated equipment, e.g. user equipment or crowd-sourcing
• CPC Class Codes: G01S 5/0264 at least one of the systems being a non-radio wave positioning system
• CPC Class Codes: H04W 4/026 using orientation information, e.g. compass
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information

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.

Claims

1. A method, comprising:

receiving data pertaining to a mobile computing device that comprises an inertial sensor, the data comprising;

an initial data packet generated by the inertial sensor in the mobile computing device, the initial data packet generated when the mobile computing device is at an initial location in an indoor environment, wherein the initial location is unknown; and

a plurality of data packets generated by the inertial sensor subsequent in time to the inertial sensor generating the initial data packet, the plurality of data packets generated by the inertial sensor 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 data packet and the plurality of data packets.

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 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 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 comprises inferring a stride length of a user of the mobile computing device based at least in part upon the initial data packet and the plurality of data packets.

8. The method of claim 1, wherein the inferring of the at least one location of the mobile computing device in the indoor environment 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.

9. The method of claim 1, wherein the data is received over the range of time, and wherein the inferring is undertaken as the data is received.

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

11. The method of claim 1, wherein the data further comprises 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.

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

13. The method of claim 1, wherein the inferring of the at least one location of the mobile computing device in the indoor environment 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.

14. The method of claim 13, 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.

15. A system, comprising:

a processor; and

a memory that comprises a plurality of components that are executed by the processor, the plurality of components comprising;

a receiver component that receives 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; and

a location inferrer component that infers 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 second data.

16. The system of claim 15, wherein the receiver component additionally receives 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 wherein the system further comprises an assignor component that assigns the signal strength value to the geographic location subsequent to the location inferrer component inferring the geographic location of the initial unknown geographic location.

17. The system of claim 15, wherein the inferrer component comprises a stride length estimator component that estimates a length of a stride of a user of the mobile computing device, and wherein the location inferrer component infers the geographic location of the initial unknown location of the mobile computing device based at least in part upon the length of the stride of the user of the mobile computing device estimated by the stride length estimator component.

18. The system of claim 15, wherein the location inferrer component infers 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.

19. The system of claim 15, further comprising an alert generator component, wherein the inferrer component infers 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 wherein the alert generator component causes a location-based alert to be presented to a user of the mobile computing device based at least in part upon the current geographic location of the mobile computing device inferred by the alert generator component.

20. A computer-readable medium comprising instructions that, when executed by a processor, cause the processor to perform acts comprising:

receiving a first data packet generated by an inertial sensor in a mobile computing device when the mobile computing device is at an initial unknown location in an 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 packet;

receiving a plurality of data packets generated by the inertial sensor in the mobile computing device when the mobile computing device is transiting in the indoor environment, the plurality of data packets generated by the inertial sensor subsequent to the first data packet;

jointly inferring a stride length of a user of the mobile computing device, a heading offset of the mobile computing device, and a current location of the mobile computing device based at least in part upon the first data packet, the plurality of data packets, and known physical constraints of the indoor environment, wherein the heading offset is an orientation of the mobile computing device relative to a direction of travel of the mobile computing device;

inferring a path of the mobile computing device in the indoor environment from the initial unknown location to a destination location based at least in part upon the jointly inferring of the stride length, the heading offset, and the current location;

receiving signal strengths observed at the mobile computing device from signals received from at least one wireless access point, the signal strengths corresponding in time to when the mobile computing device is transiting in the indoor environment; and

assigning at least one signal strength to at least one location along the path of the mobile computing device based at least in part upon the inferring of the path of the mobile computing device in the indoor environment.