INDOOR MAGNETIC FIELD BASED LOCATION DISCOVERY

• US 20130179075A1
• Filed: 01/11/2013
• Published: 07/11/2013
• Est. Priority Date: 01/11/2012
• Status: Active Grant

• Current Assignee: IndoorAtlas Oy
• Original Assignee: IndoorAtlas Oy
• Inventors: HAVERINEN, Janne
• Granted Patent: US 9,151,621 B2
• Time in Patent Office: Days
• US Class Current: 701/525
• CPC Class Codes: G01C 21/08 involving use of the magnetic field of the earth
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 5/02522 The radio-map containing measured values of non-radio values
• CPC Class Codes: G01S 5/02524 Creating or updating the radio-map
• CPC Class Codes: G01S 5/02585 at least one of the measurements being a non-radio measurement
• CPC Class Codes: G01V 3/02 operating with propagation of electric current

Abstract

There is provided an apparatus, wherein the apparatus is caused to acquire a location estimate of a positioning device that is to determine its location inside a building, wherein the location estimate is acquired on the basis of an indoor non-magnetic field based location discovery system; access an indoor Earth'"'"'s magnetic field, EMF, map of plurality of buildings, wherein the indoor EMF map represents at least one of magnitude and direction of the Earth'"'"'s magnetic field affected by the local structures of a corresponding building; and select a part of the indoor EMF map on the basis of the location estimate of the positioning device, wherein the selected part of the indoor magnetic field map includes the indoor EMF map for the area in which the positioning device currently is.

Claims

1. An apparatus, comprising:

at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to;

acquire a location estimate of a positioning device that is to determine its location inside a building, wherein the location estimate is acquired on the basis of an indoor non-magnetic field based location discovery system;

access an indoor Earth'"'"'s magnetic field, EMF, map of plurality of buildings, wherein the indoor EMF map represents at least one of magnitude and direction of the Earth'"'"'s magnetic field affected by the local structures of a corresponding building; and

select a part of the indoor EMF map on the basis of the location estimate of the positioning device, wherein the selected part of the indoor magnetic field map includes the indoor EMF map for the area in which the positioning device currently is.

2. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

apply the selected part of the indoor EMF map in an indoor EMF map-based location determination, wherein the apparatus is or is comprised in the positioning device.

3. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

provide, on request, the selected part of the indoor EMF map to the positioning device in order to allow the positioning device 400 to use the selected part of the map in locating itself.

4. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

receive at least one measured EMF vector value from the positioning device;

determine the location of the positioning device on the basis of the received at least one measured EMF vector value and the selected part of the indoor EMF map in an indoor EMF map-based location determination; and

indicate the determined location of the positioning device to the positioning device.

5. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

determine probabilities for possible locations of the positioning device on the basis of the acquired location estimate; and

limit the search space for an indoor EMF map-based location determination of the positioning device on the basis of the determined probabilities.

6. The apparatus of claim 5, wherein limiting the search space comprises applying a probability distribution in the indoor EMF map-based location determination of the positioning device, wherein the probability distribution emphasizes those locations in the EMF map which are most probable locations of the positioning device according to the determined probabilities.

7. The apparatus of claim 5, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

select the part from the EMF map on the basis of the location estimate and the determined probabilities.

8. The apparatus of claim 5, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

apply the probability distribution to the selected part of the EMF map.

9. The apparatus of claim 1, wherein the applied indoor non-magnetic field based location discovery system utilizes an indoor radio frequency base station based location discovery system.

10. The apparatus of claim 9, wherein the indoor radio frequency base station based location discovery system applies a wireless local area network.

11. The apparatus of claim 1, wherein the applied indoor non-magnetic field based location discovery system utilizes at least one air pressure sensor.

12. The apparatus of claim 1, wherein the applied indoor non-magnetic field based location discovery system utilizes radio frequency identification.

13. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

identify, on the basis of the location estimate, the building, among a plurality of buildings, in which the positioning device currently is, wherein the selected part of the indoor EMF map includes the indoor EMF map for the identified building.

14. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

identify, on the basis of the location estimate, the floor of a multi-story building in which the positioning device currently is, wherein the selected part of the indoor EMF map includes the indoor EMF map for the identified floor of the multi-story building.

15. The apparatus of claim 14, wherein the selected part of the indoor EMF map includes the indoor EMF map for the identified floor of the multi-story building and in addition the indoor EMF map for a predetermined number of adjacent floors.

16. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

detect the current location of the positioning device in the building, wherein the current location is known on the basis of at least part of the indoor EMF map and magnetic field vector measurements performed by the positioning device;

acquire at least one measurement parameter value related to the indoor non-magnetic field based location discovery system at the detected current location of the positioning device; and

apply the acquired at least one measurement parameter value for an update of a map of the indoor non-magnetic field based location discovery system.

17. The apparatus of claim 16, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

perform an update of a radio map on the basis of the acquired at least one measurement parameter value, wherein the at least one measurement parameter value comprises received signal strength of radio frequency signals.

18. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to:

adjusting the acquired location estimate further on the basis of at least one of the following;

the topology or layout of the relevant building in which the positioning device is, a detected identity of the positioning device.

19. An apparatus, comprising:

at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause a positioning device at least to;

acquire information related to a location estimate of the positioning device in a building from an indoor non-magnetic field based location discovery system;

cause a transmission of the acquired information related to the location estimate to a database entity;

cause a reception of a part of an indoor Earth'"'"'s magnetic field map, EMF, of the building, wherein the received part of the indoor EMF map is selected on the basis of the location estimate of the positioning device; and

apply the received part of the indoor EMF map in locating the positioning device in the building 100.

20. An apparatus, comprising:

at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause a positioning device at least to;

acquire information related to a location estimate of the positioning device in a building from an indoor non-magnetic field based location discovery system;

cause a transmission of the acquired information related to the location estimate to a database entity;

cause a transmission of at least one measured magnetic field vector value to the database entity in order to enable the database entity to determine the location of the positioning device on the basis of the received at least one measured magnetic field vector value and an indoor EMF map stored in the database entity; and

cause a reception of the determined location of the positioning device from the database entity.