Utilizing magnetic field based navigation
First Claim
1. An indoor location estimation and/or tracking system, comprising a cellular phone and a database server, each comprising at least one processor and at least one memory including a computer program code, wherein the respective at least one memory and the respective computer program code are configured, with the respective at least one processor, to cause the respective apparatus to perform specific actions,wherein the cellular phone is caused to:
- perform Earth'"'"'s magnetic field, EMF, vector measurements in a building, wherein the EMF vector represents magnitude and direction of the earth'"'"'s magnetic field affected by the local structures of the building; and
wirelessly transmit the measured EMF vectors to the database server, wherein the database server stores an indoor EMF map comprising EMF vector strength and direction at any given location in the building,wherein prior to location estimation of the cellular phone, a bias and/or a scaling factor of the measured EMF vectors is determined based on a difference between the measured EMF vectors and true magnetic field vectors at the location or location hypothesis of the cellular phone; and
wherein the database server is caused to;
receive the measured EMF vectors;
apply the determined bias and/or the determined scaling factor in the location estimation and/or tracking of the cellular phone;
determine a location estimate of the cellular phone in the building based on (i) the determined bias and/or the determined scaling factor, (ii) the received EMF vectors, and (iii) the indoor EMF map; and
communicate the location estimate to the cellular phone, thereby initializing the cellular phone with the location estimate.
0 Assignments
0 Petitions
Accused Products
Abstract
There is provided a solution comprising detecting that a positioning device is within a predetermined control area associated with a building, acquiring a first sequence of magnetic field measurements carried out by the positioning device, wherein the first sequence represents at least one of the magnitude and the direction of Earth'"'"'s magnetic field; determining that an operational environment of the positioning de-vice has changed between an indoor environment and an outdoor environment when a at least one predetermined criterion with respect to the first sequence is met; and causing actuation of a predetermined software function in or with respect to the positioning device when the operational environment of the positioning device has changed.
20 Citations
13 Claims
-
1. An indoor location estimation and/or tracking system, comprising a cellular phone and a database server, each comprising at least one processor and at least one memory including a computer program code, wherein the respective at least one memory and the respective computer program code are configured, with the respective at least one processor, to cause the respective apparatus to perform specific actions,
wherein the cellular phone is caused to: -
perform Earth'"'"'s magnetic field, EMF, vector measurements in a building, wherein the EMF vector represents magnitude and direction of the earth'"'"'s magnetic field affected by the local structures of the building; and wirelessly transmit the measured EMF vectors to the database server, wherein the database server stores an indoor EMF map comprising EMF vector strength and direction at any given location in the building, wherein prior to location estimation of the cellular phone, a bias and/or a scaling factor of the measured EMF vectors is determined based on a difference between the measured EMF vectors and true magnetic field vectors at the location or location hypothesis of the cellular phone; and wherein the database server is caused to; receive the measured EMF vectors; apply the determined bias and/or the determined scaling factor in the location estimation and/or tracking of the cellular phone; determine a location estimate of the cellular phone in the building based on (i) the determined bias and/or the determined scaling factor, (ii) the received EMF vectors, and (iii) the indoor EMF map; and communicate the location estimate to the cellular phone, thereby initializing the cellular phone with the location estimate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A cellular phone for use in an indoor location estimation and/or tracking system, the cellular phone 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 the cellular phone to:
-
perform Earth'"'"'s magnetic field, EMF, vector measurements in a building, wherein the EMF vector represents magnitude and direction of the earth'"'"'s magnetic field affected by the local structures of the building; wirelessly transmit the measured EMF vectors to the database server, wherein the database server stores an indoor EMF map comprising EMF vector strength and direction at any given location in the building, wherein prior to location estimation of the cellular phone, a bias and/or a scaling factor of the measured EMF vectors is determined based on a difference between the measured EMF vectors and true magnetic field vectors at the location or location hypothesis of the cellular phone, and wherein the determined bias and/or the determined scaling factor is applied in the location estimation and/or tracking of the cellular phone; determine a location estimate of the cellular phone in the building based on (i) the determined bias and/or the determined scaling factor, (ii) the received EMF vectors, and (iii) the indoor EMF map; and receive the location estimate from the database server, thereby initializing the cellular phone with the location estimate.
-
-
13. A database server for use in an indoor location estimation and/or tracking system, the database server 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 the database server to:
-
receive Earth'"'"'s magnetic field, EMF, vectors measured by a cellular phone in a building, wherein the EMF vector represents magnitude and direction of the earth'"'"'s magnetic field affected by the local structures of the building, wherein prior to location estimation of the cellular phone, a bias and/or a scaling factor of the measured EMF vectors is determined based on a difference between the measured EMF vectors and true magnetic field vectors at the location hypothesis of the cellular phone, and wherein the determined bias and/or the determined scaling factor is applied in the location estimation and/or the tracking of the cellular phone; determine a location estimate of the cellular phone in the building based on (i) the determined bias and/or the determined scaling factor, (ii) the received EMF vectors, and (iii) an indoor EMF map, wherein the database server stores the indoor EMF map comprising EMF vector strength and direction at any given location in the building; and communicate the location estimate to the cellular phone, thereby initializing the cellular phone with the location estimate.
-
Specification