Device Location Determination

• US 20150168153A1
• Filed: 12/14/2013
• Published: 06/18/2015
• Est. Priority Date: 12/14/2013
• Status: Active Grant

• Current Assignee: PNI Sensor Corporation
• Original Assignee: PNI Sensor Corporation
• Inventors: Hsu, George
• Granted Patent: US 9,109,905 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01B 7/00 Measuring arrangements characterised by the use of electric or magnetic techniques
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G01C 15/00 Surveying instruments or accessories not provided for in groups G01C1/00 - G01C13/00
• CPC Class Codes: G01C 19/00 Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
• CPC Class Codes: G01C 21/08 involving use of the magnetic field of the earth
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01R 33/00 Arrangements or instruments for measuring magnetic variables
• CPC Class Codes: G01R 33/02 Measuring direction or magnitude of magnetic fields or magnetic flux G01R33/20 takes precedence
• CPC Class Codes: G01S 19/13 Receivers
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01V 2210/142 Receiver location
• CPC Class Codes: G01V 2210/1425 Land surface
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat
• CPC Class Codes: G01V 3/165 operating with magnetic or electric fields produced or modified by the object or by the detecting device with electromagnetic waves G01V3/17
• CPC Class Codes: G01V 3/34 Transmitting data to recording or processing apparatus; Recording data
• CPC Class Codes: G01V 3/36 Recording data G01V3/34 takes precedence
• CPC Class Codes: G01V 3/40 specially adapted for measuring magnetic field characteristics of the earth

Abstract

Methods, apparatuses and systems of estimating a location of a device are disclosed. One method includes determining a first position of the device, sensing at least one magnetic anomaly at the first position, estimating a location of the magnetic anomaly relative to the first position by determining a plurality of magnetic properties of the magnetic anomaly based on sensed signals of at least a magnetic sensor, and estimating a second position of the device based on a sensed change in a distance from the magnetic anomaly to the device.

Claims

1. A method of estimating a location of a device, comprising;

determining a first position of the device;

sensing at least one magnetic anomaly at the first position;

estimating a location of the magnetic anomaly relative to the first position by determining a plurality of magnetic properties of the magnetic anomaly based on sensed signals of at least a magnetic sensor; and

estimating a second position of the device based on a sensed change in a distance from the magnetic anomaly to the device.

2. The method of claim 1, wherein the plurality of magnetic properties of the magnetic anomaly is based on sensed signals of at least the magnetic sensor, an accelerometer, and a gyro.

3. The method of claim 1, further comprising estimating additional positions of the mobile device based on additional sensing of changes in the distance of the magnetic anomaly to the mobile device.

4. The method of claim 1, wherein determining the first position comprises determining an initial position.

5. The method of claim 4, further comprising determining the initial position based on a GPS receiver of the mobile device.

6. The method of claim 1, wherein determining the first position comprises determining an initial position, and determining the first position based on the initial position and based on the sensed signals.

7. The method of claim 6, comprising determining a location of the first position based on a location of the initial position, and the sensed signals.

8. The method of claim 1, wherein sensing the at least one magnetic anomaly comprises sensing a perturbation of sensed earth magnetic vector.

9. The method of claim 1, wherein sensing the at least one magnetic anomaly comprises sensing a perturbation of dip angle between a sensed earth magnetic vector and a sensed gravity vector.

10. The method of claim 1, wherein sensing the at least one magnetic anomaly comprises sensing a perturbation of a rotation of a sensed earth magnetic vector about an axis of a sensed gravity vector.

11. The method of claim 1, wherein determining the plurality of magnetic properties of the magnetic anomaly comprises:

determining a size of a dipole associated with the magnetic anomaly;

determining an intensity of the dipole; and

determining the distance between the mobile device at the first position and the magnetic anomaly.

12. The method of claim 11, wherein one or more magnetic equations are solved for determining the size, intensity of the dipole;

and distance of the dipole.

13. The method of claim 1, wherein estimating the location of the second position comprises:

sensing the magnetic anomaly;

calculating a distance between the mobile device and the magnetic anomaly while assuming the size of the dipole associated with the magnetic anomaly and the intensity of the dipole are constant for at least a selected temporal period.

14. An apparatus, comprising;

a magnetic sensor;

a controller, wherein at least one of the controller and one or more external controllers are operative to;

determine a first position of the apparatus;

sense at least one magnetic anomaly at the first position;

estimate a location of the magnetic anomaly relative to the first position by determining a plurality of magnetic properties of the magnetic anomaly based on sensed signals of at least the magnetic sensor; and

estimate a second position of the apparatus based on a sensed change in a distance from the magnetic anomaly to the apparatus.

15. The apparatus of claim 14, further comprising an accelerometer and a gyro, and wherein the plurality of magnetic properties of the magnetic anomaly is based on sensed signals of at least the magnetic sensor, the accelerometer, and the gyro.

16. The apparatus of claim 14, wherein the at least one of the controller and one or more external controllers are further operative to:

estimate additional positions of the apparatus based on additional sensing of changes in the distance of the magnetic anomaly to the apparatus.

17. The apparatus of claim 14, wherein determining the first position comprises determining an initial position, and determining the first position based on the initial position and based on the sensed signals.

18. The apparatus of claim 14, wherein sensing the at least one magnetic anomaly comprises sensing a perturbation of sensed earth magnetic vector.

19. The apparatus of claim 14, wherein sensing the at least one magnetic anomaly comprises sensing a perturbation of dip angle between a sensed earth magnetic vector and a sensed gravity vector.

20. The apparatus of claim 14, wherein sensing the at least one magnetic anomaly comprises sensing a perturbation of a rotation of a sensed earth magnetic vector about an axis of a sensed gravity vector.

21. The apparatus of claim 14, wherein determining the plurality of magnetic properties of the magnetic anomaly comprises:

determining a size of a dipole associated with the magnetic anomaly;

determining an intensity of the dipole; and

determining the distance between the mobile device at the first position and the magnetic anomaly.