In situ combustion turbine engine airfoil inspection
View Patent ↗A system ( 10 ) for imaging a combustion turbine engine airfoil includes a camera ( 12 ) and a positioner ( 24 ). The positioner may be controlled to dispose the camera within an inner turbine casing of the engine at a first position for acquiring a first image. The camera may then be moved to a second position for acquiring a second image. A storage device ( 30 ) stores the first and second images, and a processor ( 32 ) accesses the storage device to generate a composite image from the first and second images. For use when the airfoil is rotating, the system may also include a sensor ( 40 ) for generating a position signal ( 41 ) responsive to a detected angular position of an airfoil. The system may further include a trigger device ( 42 ), responsive to the position signal, for triggering the camera to acquire an image when the airfoil is proximate the camera.
1. A system for imaging an airfoil within a combustion turbine engine comprising:
an image receptor;
a radial positioner extending through an opening in an inner turbine casing of the engine and disposing the image receptor within the casing at a first position for acquiring a first image and at a second position for acquiring a second image;
a storage device storing the first and second images; and
a processor accessing the storage device to generate a composite image from the first and second images.
2. The system of claim 1 , wherein the radial positioner further comprises a drive mechanism for rotating the radial positioner about a radial axis.
3. The system of claim 1 , further comprising a sensor generating a position signal responsive to a radial position of the image receptor within the turbine casing.
4. The system of claim 1 , further comprising:
a sensor generating a position signal responsive to a detected angular position of the airfoil as the airfoil rotates about a shaft within the turbine casing; and
a trigger device, responsive to the position signal, for triggering the image receptor to acquire an image when the airfoil is proximate the image receptor.
5. The system of claim 1 , further comprising a controller actuating the positioner to move the image receptor from the first position to the second position.
6. The system of claim 1 , further comprising an illumination source attached to the positioner for illuminating the airfoil.
7. The system of claim 6 , wherein the illumination source is selected from the group consisting of an incandescent light, a fluorescent light, a xenon strobe, a light emitting diode, a laser diode, and a fiber optic light source.
8. The system of claim 6 , wherein the illumination source is configured to emit electromagnetic energy comprising a desired wavelength.
9. The system of claim 6 , wherein the desired wavelength comprises an infrared wavelength.
10. The system of claim 6 , further comprising a wavelength filter disposed in a illumination path from the illumination source to the image receptor.
11. The system of claim 1 , wherein the image receptor comprises an infrared detector capable of sensing electromagnetic energy comprising an infrared wavelength.
12. A method for imaging an airfoil within a combustion turbine engine comprising:
disposing an image receptor within an inner turbine casing of the engine at a first position;
acquiring a first image of the airfoil at the first position;
moving the image receptor to a second position within the inner turbine casing of the engine;
acquiring a second image at the second position; and
generating a composite image from the first and second images.
13. The method of claim 12 , wherein the first and second positions are along respective lines of view perpendicular to an axis of the airfoil.
14. The method of claim 12 , wherein the first and second positions are along respective lines of view perpendicular to a surface of the airfoil.
15. The method of claim 12 , further comprising:
sensing respective radial positions of the image receptor when acquiring the first image and the second image; and
correlating respective sensed radial positions with the first image and the second image.
16. The method of claim 12 , further comprising:
detecting an angular position of the airfoil relative to its axis of rotation; and
triggering the image receptor to acquire an image when the airfoil is proximate the image receptor based on the angular position.
17. The method of claim 12 , further comprising:
detecting angular positions of the airfoil relative to its axis of rotation when acquiring the first image and the second image; and
correlating respective detected radial positions of the airfoil with the first image and the second image.
18. The method of claim 12 , further comprising:
disposing an illumination source within an inner turbine casing the engine; and
illuminating the airfoil while acquiring an image.
19. The method of claim 18 , further comprising illuminating the airfoil at an angle of less than about 30 degrees with respect to an axis of the airfoil.
20. The method of claim 18 , further comprising filtering light reflected from the airfoil to receive a desired wavelength of the light at the image receptor.
21. The method of claim 20 , wherein the wavelength of light is selected from the group consisting of a wavelength corresponding to red, blue, and green light.
22. The method of claim 12 , further comprising:
acquiring a first version of the first image using a first wavelength of electromagnetic energy;
acquiring a second version of the first image using a second wavelength of electromagnetic energy different from the first wavelength; and
processing the first and second versions of the first image to extract image details.
23. The method of claim 22 , wherein processing further comprises a subtractive process between the versions.
24. The method of claim 22 , wherein processing further comprises an additive process between the versions.