Scanning system with stereo camera set

• US 20060182308A1
• Filed: 03/08/2004
• Published: 08/17/2006
• Est. Priority Date: 03/07/2003
• Status: Active Grant

• Current Assignee: Dimensional Technology International, Inc.
• Original Assignee: Dimensional Technology International, Inc.
• Inventors: Gerlach, Dieter, Kellner, Helmut
• Granted Patent: US 7,639,372 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G01B 11/2545 with one projection direction and several detection directions, e.g. stereo
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/0006 using a design-rule based approach
• CPC Class Codes: G06T 7/593 from stereo images

Abstract

A scanning system includes one or more stereo camera sets (10) for detecting qualitative and quantitative anomalies of an object (40). Each stereo camera set (10) includes two cameras (12, 14) and a projector (16). Each camera (12, 14) is calibrated to correct any distortion due to misalignment of the CCD matrix array (18) and deficiencies of the optical system. The projector (16) projects an absolute encoded pattern (32, 34, 36) onto the object (40) to be measured and is capable of varying the intensity of the emitted electromagnetic energy in the infrared, visible and ultraviolet spectrums. A plurality of camera sets (10) can be combined in a scanning system matrix (42, 44) capable of detecting anomalies of the object (40) in a three-dimensional room (26). The three-dimensional room (26) can be of any desirable size, depending on the number of stereo camera sets (10). The data from the cameras (12, 14) is pre-processed by gate arrays (62) before being transmitted via digital signal processors (66) to a computer interface (64) for display of the measurement. As a result, the amount of data transferred is streamlined, thereby reducing operating time and enabling the scanning system to very accurately detect anomalies of the object (40) in a very short period of time.

Claims

1. A scanning system comprising a stereo camera set (10) including a pair of calibrated cameras (12, 14), a projector (16) having a medium with absolute encoded pattern (32) thereon, and a light source (38) for projecting the absolute encoded pattern (32) on a surface of an object (40), wherein said scanning system detects an anomaly on a surface of the object (40) when the object (40) is placed within a three-dimensional room (26).

2. The scanning system according to claim 1, further comprising a plurality of camera sets (10) arranged in a scanning matrix (42, 44) for scanning the surface of the object (40) in the three-dimensional room (26).

4. The scanning system according to claim 1, wherein the light source (38) of said projector (16) is capable of emitting electromagnetic energy at three different frequencies onto a surface of the object (40), the light source (38) capable of varying an intensive of each of the three frequencies of electromagnetic energy.

5. The scanning system according to claim 4, wherein the intensity of electromagnetic energy is a function of a surface characteristic of said object (40).

6. The scanning system according to claim 4, wherein the projector (16) emits the absolute encoded pattern (42, 44) in both a first direction and a second direction.

7. The scanning system according to claim 4, wherein the electromagnetic energy is in the form of visible light.

8. The scanning system according to claim 4, wherein the frequency and intensity of said electromagnetic energy varies as a function of time.

16. The scanning system according to claim 1, wherein the absolute encoded pattern (32) comprises a stripe pattern (34).

17. The scanning system according to claim 1, wherein the absolute encoded pattern (32) comprises a round pattern (36).

18. The scanning system according to claim 1, wherein each camera (12, 14) is calibrated by measuring a position of each dot (20) of a dot matrix reference system (18) within a field of view (22) of each camera (12, 14).

19. The scanning system according to claim 1, wherein the camera set (10) is calibrated by rotating a dot matrix reference system (18) while the stereo camera set (10) is located at a selected elevation, and then repeating the calibration at a different selected elevation, thereby defining the three-dimensional room (26).

20. The scanning system according to claim 1, wherein the object (40) is recognized by the stereo camera set (10) by using a hierarchical arrangement (60) in which a gate array (62) determines which data from an array of data is necessary for recognition of the object (40).

3. (canceled)

9. A method of processing data in a scanning system, comprising the steps of:

calibrating each camera (12, 14) of a stereo camera set (10);

processing an array of data from scanning a surface of an object (40) with a the stereo camera set (10) by using a hierarchical arrangement (60) in which a gate array (62) connected to a camera (12, 14) of the stereo camera set (10) determines which data from the array of data is necessary for recognition of the object (40), and which data from the array of data is necessary for computer interface operation;

transmitting only data from the array of data which is necessary for computer interface operation via a digital signal processor (66) to a computer (64); and

displaying the data which is necessary for computer interface operation on the computer (64).

10. The method of claim 9, wherein the array of data from measurement of the object (40) is processed by parallel processing.

11. The method of claim 9, further comprising the step of calibrating the stereo camera set (10) prior to measuring the object (40).

12. The method of claim 11, wherein stereo camera set (10) is calibrated by rotating a reference matrix pattern while the stereo camera set (10) is located at a selected elevation, and then repeating the calibration at a different selected elevation, thereby defining a three-dimensional room (26).

13. The method of claim 9, further comprising the step of arranging a plurality of stereo camera sets (10) in a scanning matrix (42, 44) for scanning the surface of the object (40) in a three-dimensional room (26).

14. The method of claim 13, further comprising the step of calibrating the scanning matrix prior to scanning the surface of the object (40).

15. (canceled)