Position detecting apparatus and method of correcting data therein

• US 20060114320A1
• Filed: 11/23/2005
• Published: 06/01/2006
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: Arriver Software AB (Qualcomm, Inc.)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Saka, Masakazu, Nagaoka, Nobuharu, Watanabe, Masahito
• Granted Patent: US 7,620,237 B2
• Time in Patent Office: Days
• US Class Current: 348/118
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06T 7/85 Stereo camera calibration

Abstract

Two aiming targets are arranged at positions that are away from two infrared cameras by a predetermined distance. One of the infrared cameras images one of the aiming targets, and the other of the infrared cameras images the other of the aiming targets. Assuming that the obtained images relate to an image of one aiming target, a parallax offset value is calculated. The correction of position is performed based on the parallax offset value.

Claims

1. An apparatus for detecting a position in an actual space of an object by imaging said object with a plurality of imaging units, comprising:

an object extracting unit for extracting an object from images obtained by said imaging units;

an actual space position calculating unit for calculating said position in said actual space of said object extracted by said object extracting unit;

a corrective value calculating unit for calculating a corrective value to correct said position in said actual space calculated by said actual space position calculating unit; and

an actual space position correcting unit for correcting said position in said actual space calculated by said actual space position calculating unit by using said corrective value calculated by said corrective value calculating unit,

wherein said corrective value calculating unit images a plurality of objects arranged at predetermined positions in said actual space with said imaging units, and calculates said corrective value based on positions in images of said objects.

2. An apparatus according to claim 1, wherein said corrective value calculating unit images said objects arranged at predetermined positions in said actual space with said imaging units, respectively, and calculates said corrective value based on said positions in said images of said objects.

3. An apparatus according to claim 2, further comprising a virtual parallax calculating unit for calculating a distance between said objects in said images obtained by said imaging units as a virtual parallax,

wherein said corrective value calculating unit calculates said corrective value based on said virtual parallax.

4. An apparatus according to claim 1, wherein said corrective value calculating unit calculates said corrective value based on:

a distance between said objects arranged at predetermined positions in said actual space, said distance being obtained in a direction in which said imaging units are arranged; and

a distance between said objects and said imaging units obtained when said objects are arranged in said direction in which said imaging units are arranged.

5. An apparatus according to claim 2, wherein said distance between said objects is equal to a distance between said imaging units.

6. An apparatus according to claim 1, wherein said actual space position calculating unit comprises a parallax calculating unit for calculating each of parallaxes obtained when each of said objects is imaged by said imaging units,

wherein said corrective value calculating unit calculates said corrective value based on said parallaxes of said objects arranged at predetermined positions in said actual space.

7. An apparatus according to claim 6, wherein said corrective value calculating unit calculates said corrective value based on a distance between said objects obtained in a direction perpendicular to a direction in which said imaging units are arranged.

8. An apparatus for detecting a position in an actual space of an object by imaging said object with two imaging units, comprising:

a virtual parallax calculating unit for calculating a distance between a first object and a second object in images as a virtual parallax, said first object and said second object being arranged in a direction in which first and second imaging units are arranged, a predetermined distance being provided between said first object and said second object, said first imaging unit obtaining said image of said first object, said second imaging unit obtaining said image of said second object,

a parallax corrective value calculating unit for calculating a difference between said virtual parallax and a reference virtual parallax as a parallax corrective value, where said reference virtual parallax is defined as a distance between said first object and said second object in images when optical axes of said first and second imaging units are parallel to each other,

wherein a parallax in images of one object obtained by said first and second imaging units is corrected by using said parallax corrective value.

9. An apparatus according to claim 8, wherein said predetermined distance between said first object and said second object is equal to a base length between said first imaging unit and said second imaging unit, and wherein said parallax corrective value calculating unit calculates said virtual parallax as said parallax corrective value.

10. An apparatus for detecting a position in an actual space of an object by imaging said object with two imaging units, comprising:

a first parallax calculating unit for calculating a first parallax between an image of a first object obtained by a first imaging unit and an image of said first object obtained by a second imaging unit;

a second parallax calculating unit for calculating a second parallax between an image of a second object obtained by said first imaging unit and an image of said second object obtained by said second imaging unit;

a parallax corrective value calculating unit for calculating a parallax corrective value based on said first parallax, said second parallax and a distance between said first object and said second object,

wherein said first object and said second object are arranged such that a distance from said first and second imaging units to said first object is different from a distance from said first and second imaging units to said second object, and said distance is obtained in a direction perpendicular to a direction in which said first and second imaging units are arranged, and

wherein a parallax in images of one object obtained by said first and second imaging units is corrected by using said parallax corrective value.

11. A method of correcting data in an apparatus that detects a position in an actual space of an object by imaging said object with a plurality of imaging units, said method comprising the steps of:

arranging a plurality of objects at predetermined positions in said actual space;

obtaining images of said objects with said imaging units; and

calculating a corrective value to correct said position in said actual space based on said positions in said obtained images of said objects,

wherein an arbitrary object is imaged by said imaging units for obtaining images of said arbitrary object, and a position in one of said obtained image of said arbitrary object is corrected by using said corrective value.

12. A method of correcting data in an apparatus that detects a position in an actual space of an object by imaging said object with two imaging units, said method comprising the steps of:

arranging a first object and a second object, said first object and said second object being away from each other by a predetermined distance in a direction in which first and second imaging units are arranged;

obtaining an image of said first object with said first imaging unit;

obtaining an image of said second object with said second imaging unit;

calculating a distance between said first object and said second object in said images as a virtual parallax; and

calculating a difference between said virtual parallax and a reference virtual parallax as a parallax corrective value, where said reference virtual parallax is defined as a distance between said first object and said second object in images when optical axes of said first and second imaging units are parallel to each other,

wherein a parallax in images of an arbitrary object obtained by said first and second imaging units is corrected by using said parallax corrective value.

13. A method according to claim 12, wherein said reference virtual parallax dn is calculated by an equation:

dn=f/p·

(B−

D)/Zn

where f is a focal length of said first and second imaging units, p is a pixel pitch, B is a base length between said first and second imaging units, D is a distance between said first object and said second object obtained in said direction in which said first and second imaging units arranged, Zn is a distance between said first and second objects and said first and second imaging units obtained when said first and second objects are arranged in said direction in which said first and second imaging units are arranged.

14. A method of correcting data in an apparatus that detects a position in an actual space of an object by imaging said object with two imaging units, said method comprising the steps of:

arranging a first object and a second object such that a distance from first and second imaging units to said first object is different from a distance from said first and second imaging units to said second object;

obtaining an image of said first and second objects with said first imaging unit;

obtaining an image of said first and second objects with said second imaging unit;

calculating a first parallax between said image of said first object obtained by said first imaging unit and said image of said first object obtained by said second imaging unit;

calculating a second parallax between said image of said second object obtained by said first imaging unit and said image of said second object obtained by said second imaging unit;

calculating a parallax corrective value based on said first parallax, said second parallax and a distance between said first object and said second object, said distance being obtained in a direction perpendicular to a direction in which said first and second imaging units are arranged; and

correcting a parallax in images of one object obtained by said first and second imaging units by using said parallax corrective value.

15. A method according to claim 14, wherein said parallax corrective value α

is calculated by equations;

Zn−

E=f/p·

B/(dn1−

α

)
Zn=f/p·

B/(dn2−

α

)

where f is a focal length of said first and second imaging units, p is a pixel pitch, B is a base length between said first and second imaging units, dn1 is said first parallax, dn2 is said second parallax,

E is said distance between said first and second objects obtained in said direction perpendicular to said direction in which said first and second imaging units are arranged, Zn is a distance between said second object and said first and second imaging units.

16. An apparatus for detecting a position in an actual space of an object by imaging said object with a plurality of imaging units, comprising:

an object extracting unit for extracting an object from images obtained by said imaging units;

an actual space position calculating unit for calculating said position in said actual space of said object extracted by said object extracting unit;

a corrective value calculating unit for calculating a corrective value to correct said position in said actual space calculated by said actual space position calculating unit; and

an actual space position correcting unit for correcting said position in said actual space calculated by said actual space position calculating unit by using said corrective value calculated by said corrective value calculating unit,

wherein said corrective value calculating unit images a plurality of objects with said imaging units, said objects respectively arranged on lines connecting a specified point in said actual space and said imaging units, and calculates said corrective value based on positions in images of said objects.

17. An apparatus according to claim 16, wherein said corrective value calculating unit images said objects arranged on said lines with said imaging units, respectively, and calculates said corrective value based on said positions in said images of said objects.

18. An apparatus according to claim 17, further comprising a virtual parallax calculating unit for calculating a distance between said objects in said images obtained by said imaging units as a virtual parallax,

wherein said corrective value calculating unit calculates said corrective value based on said virtual parallax.

19. A method of correcting data in an apparatus that detects a position in an actual space of an object by imaging said object with a plurality of imaging units, said method comprising the steps of:

arranging a plurality of objects on lines connecting a specified point in said actual space and said imaging units;

obtaining images of said objects with said imaging units; and

calculating a corrective value to correct said position in said actual space based on positions in said obtained images of said objects,

wherein an arbitrary object is imaged by said imaging units, and a position in one of said obtained images of said arbitrary object is corrected by using said corrective value.