Three-dimensional imaging system for robot vision

• US 20070188883A1
• Filed: 12/28/2005
• Published: 08/16/2007
• Est. Priority Date: 03/22/2004
• Status: Active Grant

• Current Assignee: Anstrom, Inc., Stereo D Inc., Stereo Display, Inc.
• Original Assignee: Angstrom, Inc., Stereo Display, Inc.
• Inventors: Seo, Cheong, Cho, Gyoung, Baek, Sang
• Granted Patent: US 7,410,266 B2
• Time in Patent Office: Days
• US Class Current: 359/676
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B

Abstract

The present invention provides a three-dimensional imaging system for robot vision, which is capable of three-dimensional positioning of objects, object identification, searching and tracking of an object of interest, and compensating the aberration of the system. The three-dimensional imaging system for robot vision comprises one or more camera systems, each of which has at least one variable focal length micromirror array lens, an imaging unit, and an image processing unit. The variable focal length micromirror array lens used in the three-dimensional imaging system for robot vision has unique features including a variable focal length, a variable focal axis, and a variable field of view with a fast response time.

Claims

1. A three-dimensional imaging system for robot vision comprising:

(a) a lens system, comprising a variable focal length micromirror array lens (MMAL), configured to change the focal plane by changing the focal length of the variable focal length MMAL;

(b) an imaging unit, optically coupled to the lens system, configured to receive an object image from the lens system and to sense the object image; and

(c) an image processing unit, communicatively coupled to the imaging unit, configured to process the object images sensed by the imaging unit and to generate an all-in-focus image and three-dimensional position information of the object.

2. The three-dimensional imaging system for robot vision of claim 1, wherein the imaging unit comprises at least one two-dimensional image sensor taking the two-dimensional images at different focal planes, wherein the focal plane is changed by change of focal length of the variable focal length MMAL.

3. The three-dimensional imaging system for robot vision of claim 1, wherein the lens system further comprises an auxiliary lens or group of lenses to change the field of view of the lens system.

4. The three-dimensional imaging system for robot vision of claim 1, wherein the lens system further comprises one or more auxiliary lenses to increase the numerical aperture of the lens system.

5. The three-dimensional imaging system for robot vision of claim 1, wherein the lens system further comprises an auxiliary lens or group of lenses to change the image resolution of the three-dimensional imaging system.

6. The three-dimensional imaging system for robot vision of claim 1, wherein the lens system with the variable focal length MMAL further comprises another variable focal length MMAL for a variable field of view.

7. The three-dimensional imaging system for robot vision of claim 1, wherein the variable focal length MMAL comprises a plurality of micromirrors.

8. The three-dimensional imaging system for robot vision of claim 7, wherein each micromirror is controlled to change the focal length of the variable focal length MMAL.

9. The three-dimensional imaging system for robot vision of claim 7, wherein each micromirror is controlled to change the optical axis of the lens system.

10. The three-dimensional imaging system for robot vision of claim 1, wherein the imaging system can perform the automatic focusing function.

11. The three-dimensional imaging system for robot vision of claim 1, wherein the variable focal length MMAL compensates the aberration of the system.

12. The three-dimensional imaging system for robot vision of claim 1, further comprising an object identification unit using all-in-focus images received from the image processing unit.

13. The three-dimensional imaging system for robot vision of claim 12, wherein the object identification unit uses three-dimensional position information of the object received from the image processing unit.

14. The three-dimensional imaging device for robot vision of claim 1, wherein the imaging processes to obtain an all-in-focus image and three-dimensional position information of the object is achieved faster than the persistent rate of the human eye.

15. The three-dimensional imaging system for robot vision of claim 1, further comprising an optical tracking unit, coupled to the lens system, configured to change the optical axis of the lens system by changing the optical axis of the variable focal length MMAL to track an object of interest.

16. The three-dimensional imaging system for robot vision of claim 15, wherein the optical tracking unit is coupled to the lens system, configured to change the field of view of the lens system by changing the focal length of the variable focal length MMALs.

17. The three-dimensional imaging system for robot vision of claim 15, wherein the optical tracking unit includes a time sharing algorithm to use a wide field of view for searching and a narrow field of view for identifying and tracking the object of interest.

18. The three-dimensional imaging system for robot vision of claim 15, wherein the optical tracking unit is coupled to the lens system, configured to measure the distance to the object of interest.

19. The three-dimensional imaging system for robot vision of claim 15, wherein the optical tracking unit is coupled to the lens system, configured to measure the size of the object of interest.