Location and path-map generation data acquisition and analysis systems

• US 20100017124A1
• Filed: 07/17/2008
• Published: 01/21/2010
• Est. Priority Date: 07/17/2008
• Status: Active Grant

• Current Assignee: Memsic Semiconductor (Wuxi) Co., Ltd. (MZ Investment Holdings Ltd.)
• Original Assignee: Memsic Incorporated (MZ Investment Holdings Ltd.)
• Inventors: Liang, Jin, Zhao, Yang
• Granted Patent: US 8,577,595 B2
• Time in Patent Office: Days
• US Class Current: 701/212
• CPC Class Codes: G01C 21/1654 with electromagnetic compass
• CPC Class Codes: G01C 21/1656 with passive imaging devices, e.g. cameras
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30252 Vehicle exterior; Vicinity of vehicle
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

A device, system, and method for generating location and path-map data for displaying a location and path-map is disclosed. The device includes a first set of sensors for generating a plurality of first data signals with respect to an attitude of an object; a second set of sensors for generating a plurality of second data signals with respect to the attitude of the object; an imaging device for generating a plurality of third data signals that include a most significant feature, which is disposed in at least two images of the imaging device; and at least one processing device that is adapted to calculate a heading direction (bearing) of the device using the plurality of first data signals and the plurality of second data signals; to calculate a distance traveled along the heading direction using the plurality of third data signals; and to translate the calculated heading direction and calculated distance traveled into a leg or portion of a leg of a path-map for visual display on a two- or three-dimensional system.

Claims

1. A device for generating location and path-map data for displaying a location and path-map, the device comprising:

a first set of sensors for generating a plurality of first data signals with respect to an attitude of an object;

a second set of sensors for generating a plurality of second data signals with respect to the attitude of the object;

an imaging device for generating a plurality of third data signals that include a most significant feature, which is disposed in at least two images of the imaging device;

at least one processing device that is adapted to calculate a heading direction (bearing) of the device using the plurality of first data signals and the plurality of second data signals;

to calculate a distance traveled along the heading direction using the plurality of third data signals; and

to translate the calculated heading direction and calculated distance traveled into a leg or portion of a leg of a path-map for visual display on a two- or three-dimensional system.

2. The device as recited in claim 1, wherein the first set of sensors includes a set of magnetic sensors that are structured and arranged to generate first data signals corresponding to magnetic field strength about three orthogonal axes.

3. The device as recited in claim 1, wherein the second set of sensors includes a set of inertial sensors that are structured and arranged to generate second data signals corresponding to accelerations along two or three orthogonal axes.

4. The device as recited in claim 1, wherein the imaging device is structured and arranged to generate third image data signals at a predetermined, fixed frequency.

5. The device as recited in claim 1, wherein the at least one processing device includes:

a signal processing device that is electrically coupled to the plurality of first and second set of sensors; and

an image processing device that is electrically coupled to the imaging device and to the signal processing device.

6. The device as recited in claim 5, wherein the at least one processing device further includes a main controller that is electrically coupled to each of the signal processing device and the image processing device.

7. The device as recited in claim 1, wherein the first set of sensors includes a three-axis electronic compass.

8. The device as recited in claim 1, wherein the second set of sensors includes a two- or three-axis accelerometer.

9. The device as recited in claim 1, wherein the at least one processing device calculates heading direction (α

) using the equation;

α

=tan<sup>−

1</sup>(M_yh/M_xh)

where M_xh=M_x·

cos θ

+M_y·

sin θ

·

sin φ

+M_z·

cos θ

·

sin φ

and M_yh=M_y·

cos θ

−

M_z·

sin θ

,

in which M_xh refers to the magnetic field strength about the x-axis in a horizontal plane;

M_yh refers to the magnetic field strength about the y-axis in the horizontal plane;

θ

(theta) is the roll of the object and φ

(phi) is the pitch of the object.

10. The device as recited in claim 1, wherein the at least one processing device calculates the distance traveled by first calculating a demagnification number using a relationship between at least one dimension of a first image of the most significant feature and a second, larger image of said most significant feature.

11. The device as recited in claim 1, wherein the at least one processing device translates the calculated heading direction and the calculated distance traveled into a leg vector or portion of a leg vector.

12. A method of providing data for generating and displaying a location or path-map on a device or system, the method comprising:

generating a plurality of first data signals with respect to an attitude of an object;

generating a plurality of second data signals with respect to the attitude of the object;

generating a plurality of third data signals that include a most significant feature that appears in at least two images of the imaging device;

calculating a heading direction (bearing) using the plurality of first data signals and the plurality of second data signals;

calculating a distance traveled along the heading direction using the plurality of third data signals; and

translating the calculated heading direction and calculated distance traveled into a leg or portion of a leg of a path-map for visual display on the device or system.

13. The method as recited in claim 12, wherein generating the first data signals includes generating data signals corresponding to magnetic field strength about three orthogonal axes using magnetic sensors.

14. The method as recited in claim 12, wherein generating the second data signals includes generating signals corresponding to accelerations along two or three orthogonal axes using inertial sensors.

15. The method as recited in claim 12, wherein generating third image data signals occurs at a predetermined, fixed frequency.

16. The method as recited in claim 12, wherein heading direction (α

) is calculated using the equation;

α

=tan<sup>−

1</sup>(M_yh/M_xh)

where M_xh=M_x·

cos φ

+M_y·

sin θ

·

sin φ

+M_z·

cos θ

·

sinφ

and M_yh=M_y·

cos θ

−

M_z·

sin θ

,

in which M_xh refers to the magnetic field strength about the x-axis in a horizontal plane;

M_yh refers to the magnetic field strength about the y-axis in the horizontal plane;

θ

(theta) is the roll of the object and φ

(phi) is the pitch of the object.

17. The method as recited in claim 12, wherein calculating the distance traveled includes:

identifying a most significant image common to successive images; and

calculating a demagnification number using a relationship between at least one dimension of a first image of the most significant feature and a second, larger image of said most significant feature.

18. The method as recited in claim 17, further comprising:

determining when an appreciable change in at least one or heading direction (bearing), magnetic field strength, and acceleration occurs; and

identifying a second most significant image common to successive images; and

calculating a subsequent demagnification number using a relationship between at least one dimension of a first image of the second most significant feature and a second, larger image of said second most significant feature.

19. A system for displaying location and path-map data, the system comprising:

a first set of sensors for generating a plurality of first data signals with respect to an attitude of an object;

a second set of sensors for generating a plurality of second data signals with respect to the attitude of the object;

an imaging device for generating a plurality of third data signals that include a most significant feature, which is disposed in at least two images of the imaging device;

a first processing device that is adapted to calculate a heading direction (bearing) of the device using the plurality of first data signals and the plurality of second data signals;

a second processing device that is adapted to calculate a distance traveled along the heading direction using the plurality of third data signals;

a third processing device that is adapted to translate the calculated heading direction and the calculated distance traveled into a leg or portion of a leg of a path-map; and

a two- or three-dimensional display screen for displaying the leg or leg portion.