Method and system for determining and tracking an indoor position of an object

Patent metadata

Field	Value
Publication number	US-11743687-B2
Application number	US-202117224246-A
Country	US
Kind code	B2
Filing date	Apr 7, 2021
Priority date	Oct 31, 2017
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

According to an example aspect of the present invention, there is provided a method and system for determining and tracking an indoor position of an object, the method comprising: using a primary position indication, based on signals received from an external positioning system of at least two different positions of said object to calibrate tracking of a secondary position indication, which is an indoor position, and wherein the tracking of the secondary position comprises: recording acceleration data of a second part of the object, integrating said acceleration data, determining a characteristic position of the cyclically moving second part of the object in subsequent cycles, measuring a geomagnetic first orientation of the second part of the object in said characteristic position, determining the second direction of movement of the first part of the object, computing a velocity of the object in any direction based on the acceleration data, and determining the secondary position indication of said object based on said direction data and said velocity data.

First claim

The invention claimed is:

1. A method for determining and tracking an indoor position of an object comprising
using a primary position indication, based on signals received from an external positioning system of at least two different positions of said object to calibrate tracking of a secondary position indication, which is an indoor position, and wherein after calibrated, the tracking of the secondary position comprises:
recording acceleration data of a second part of the object, which second part is cyclically moving relative to the first part of the object, over a plurality of cycles using a sensor attached to the second part of the object,
integrating said acceleration data over at least one cycle of movement to determine a tilting of said cyclically moving part of the object relative to a horizontal plane,
determining a characteristic position of the cyclically moving second part of the object in subsequent cycles,
measuring a geomagnetic first orientation of the second part of the object in said characteristic position,
determining the second direction of movement of the first part of the object by measuring a geomagnetic second orientation of the second part of the object in said characteristic position, and wherein the determination is based on the tilting and the deviation between the geomagnetic first orientation and the geomagnetic second orientation of the second part of the object,
computing a velocity of the object in any direction based on the acceleration data, and

determining the secondary position indication of said object based on said direction data and said velocity data, wherein the secondary position indication is used to determine the indoor position of said object,
wherein at least one of:
a first angle between the geomagnetic first orientation of the second part of the object and the first direction of the first part of the object; or
a second angle between the geomagnetic first orientation and the geomagnetic second orientation of the second part of the object is determined.

2. The method according to claim 1 , comprising continuously tracking and computing at least one of the direction and the velocity of the moving object, and said secondary position indication.

3. The method according to claim 1 , wherein a third angle between the geomagnetic second orientation of the second part of the object and the second direction of the first part of the object is identical with the first angle.

4. The method according to claim 1 , wherein a position of the first part of the object is determined with the use of at least one of: an accelerometer or an inertial sensor to determine the acceleration data, a magnetometer to determine the geomagnetic orientation of the second part of the object, and a timing function used to record the time the object has moved in any direction.

5. The method according to claim 1 , wherein the time the object has moved in any direction is recorded by a timing function.

6. The method according to claim 1 , wherein the calibration is personalized such that different accelerations are measured by acceleration sensors even when the velocities are identical.

7. The method according to claim 1 , wherein air pressure is measured by means of an air pressure sensor and an altitude of said object is determined based on the air pressure.

8. The method according to claim 1 , wherein the secondary position indication of the moving object is displayed on a display of a system, transmitted from the system to another device, or shown on a map which is available via internet.

9. The method according to claim 1 , wherein the primary position indication is determined based on GPS signals.

10. The method according to claim 1 , wherein the secondary position indication is determined in real time or at a later stage.

11. The method according to claim 1 , wherein the characteristic position of each cycle is at a maximum or minimum acceleration value.

12. The method according to claim 1 , wherein a track formed in a first coordinate system is aligned with a second coordinate system.

13. A system for determining and tracking an indoor position of an object, the system comprising:
a receiver for receiving signals from an external positioning system,
at least one of an accelerometer and an inertial sensor,
a magnetometer,
at least one memory unit, and
a processing unit comprising at least one processing core, at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processing core, cause the system at least to:
use a primary position indication, based on signals received from an external positioning system of at least two different positions of said object to calibrate tracking of a secondary position indication, which is an indoor position,
record acceleration data of a second part of the object, which second part is cyclically moving relative to the first part of the object, over a plurality of cycles using an accelerometer or inertial sensor attached to the second part of the object,
integrate said acceleration data over at least one cycle of movement to determine the tilting of said cyclically moving part of the object relative to the horizontal plane,
determine a characteristic position in subsequent cycles,
measure a geomagnetic first orientation of the second part of the object in a characteristic position of subsequent cycles using a magnetometer,
measure a geomagnetic second orientation of the second part of the object in the characteristic position of each cycle using the magnetometer,
determine a second direction of the first part of the moving object based on the tilting and a deviation between the geomagnetic first orientation and the geomagnetic second orientation of the second part of the object,
compute a velocity of the object in any direction based on the acceleration data, and
determine the secondary position indication of said object based on said direction data and said velocity data, wherein the secondary position indication is used to determine the indoor position of said object,

wherein the system is configured to determine at least one of a first angle between the geomagnetic first orientation of the second part of the object and the first direction of the first part of the object or a second angle between the geomagnetic first orientation and the geomagnetic second orientation of the second part of the object.

14. The system according to claim 13 , wherein the processing unit is configured to continuously compute and store at least one of the direction, the velocity, and the secondary position indication of the moving object.

15. The system according to claim 13 , wherein the system is configured to determine the primary position indication of the object based on GPS signals between two separate points of time.

16. The system according to claim 13 , wherein the system is configured to track at least one of the first direction, the second direction, an acceleration, the velocity and a position of the first part of the moving object.

17. The system according to claim 13 , wherein the system is configured to determine a position of the object with the use of at least one of: the accelerometer or inertial sensor to determine the acceleration data, the magnetometer to determine the first orientation and the second orientation of the second part of the object, and a timing function used to record the time the object has moved in any direction.

18. The system according to claim 13 ,

Assignees

• Suunto Oy

Inventors

• Hapola Tuomas
• Nieminen Heikki
• Martikka Mikko
• Lindman Erik

Classifications

• H04W4/029 Primary

  Location-based management or tracking services · CPC title

• A63B24/0021

  Tracking a path or terminating locations · CPC title

• G01C17/28

  Electromagnetic compasses (with north seeking magnetic elements and having electric pick-offs G01C17/26) · CPC title

• G01C21/08

  involving use of the magnetic field of the earth · CPC title

• G01C21/1654

  with electromagnetic compass · CPC title