Automated adaptive machining of obstructed passages

1. A process for automated machining of an obstructed passage of an article, the process comprising:

establishing a local reference coordinate system using characteristic features of the article that are unaffected by subsequent machining;

obtaining over a plurality of angles thee-dimensional position and orientation data of the passage as local coordinates with respect to the reference coordinate system, using an automated scanning vision system and a distance measurement device;

saving position and orientation data of the passage; and

removing obstructing material from the passage using the saved position and orientation data of the passage.

2. A process according to claim 1 comprising:

establishing a local tangential surface plane using a touch probe, an eddy current sensor, an optical triangulation sensor, a conoscopic sensor, an interferometer, an optical distance measurement device, or combinations thereof; and

wherein obtaining comprises obtaining the position data of the passage from the intersection of the axis of the passage with the local tangential surface plane.

3. A process according to claim 1 , wherein corners, rims, side surfaces, grooves, or combinations thereof, are used to establish the local reference coordinate system.

4. A process according to claim 1 , wherein removing obstructing material comprises removing by laser evaporation using a high power Q-switched laser or precision drilling solid state laser.

5. A process according to claim 1 , wherein removing obstructing material comprises removing with a Q-switched ND-YAG laser having a power intensity in the range from 2*10 7 to 5*10 8 W/cm 2 .

6. A process according to claim 1 , wherein removing obstructing material comprises removing by water jet drilling.

7. A process according to claim 1 , wherein obtaining the position and orientation data of the passage comprises obtaining with a first robot or CNC-system, and removing obstructing material comprises removing with a second robot or CNC-system, different from the first robot or CNC-system.

8. A process according to claim 1 , wherein obtaining the position and orientation data of the passage comprises obtaining with a first robot or CNC-system, and removing obstructing material comprises removing with said first robot or CNC-system.

9. A process according to claim 1 , further comprising:

establishing an error map using a reference article; and

compensating for residual deviations between position data indicated by the robot and the actual, absolute position data.

10. A process according to claim 1 , further comprising:

deriving the orientation of the passage from the thee-dimensional position and orientation data of the passage; and

determining the optimal alignment with the passage with image analysis tools.

11. A process according to claim 1 , wherein the article is a superalloy turbine component having cooling passages, and further comprising:

recoating the turbine component prior to said establishing a local reference coordinate system.

12. A process for automated machining of an obstructed passage of an article, the process comprising:

establishing a local reference coordinate system using characteristic features of the article that are unaffected by subsequent machining;

determining a local tangential surface using a distance measurement device;

taking at a plurality of angles images of the obstructed passage using a scanning vision system and determining the passage axis using image analysis tools;

obtaining position data from the intersection of the passage axis with the local tangential surface as local coordinates with respect to the reference coordinate system;

saving position and passage axis data of the passage; and

removing obstructing material from the passage using the saved position and axis data of the passage.

13. A process according to claim 12 , wherein determining a local tangential surface comprises determining with a touch probe, an eddy current sensor, an optical triangulation sensor, a conoscopic sensor, an interferometer, an optical distance measurement device, or combinations thereof.

14. A process according to claim 12 , wherein corners, rims, side surfaces, grooves, or combinations thereof, are used to establish the local reference coordinate system.

15. A process according to claim 12 , wherein removing obstructing material comprises removing by laser evaporation using a high power Q-switched laser or precision drilling solid state laser.

16. A process according to claim 12 , wherein removing obstructing material comprises removing with a Q-switched ND-YAG laser having a power intensity in the range from 2*10 7 to 5*10 8 W/cm 2 .

17. A process according to claim 12 , wherein removing obstructing material comprises removing by water jet drilling.

18. A process according to claim 12 , wherein obtaining the position and determining axis data of the passage comprise obtaining with a first robot or CNC-system, and removing obstructing material comprises removing with a second robot or CNC-system different from the first robot or CNC-system.

19. A process according to claim 12 , wherein obtaining the position and determining axis data of the passage comprise obtaining with a first robot or CNC-system, and removing obstructing material comprises removing with said first robot or CNC-system.

20. A process according to claim 12 , further comprising:

establishing an error map using a reference article; and

compensating for residual deviations between position data indicated by the robot and the actual, absolute position data.

21. A process according to claim 12 , further comprising:

deriving the orientation of the passage from the axis and orientation data of the passage; and

determining the optimal alignment with the passage with image analysis tools.

22. A process according to claim 12 , wherein the article is a superalloy turbine component having cooling passages, and further comprising:

recoating the turbine component prior to said establishing a local reference coordinate system.