Nondestructive coating imperfection detection system and method therefor
A nondestructive coating inspection system to inspect a component without removal of a coating thereon, the system including an airflow source to directed heated or cooled air into the component; a sensor directed toward the component to generate an infrared radiation image data of component heated by the heated or cooled air; and a controller in communication with the sensor to register the current infrared radiation image data to at least one infrared reference image data to classify the component based on the comparing.
1. A nondestructive coating inspection system, the system comprising:
an airflow source to direct one or more of heated and cooled air into a component;
a sensor directed toward the component to generate an infrared radiation image data of the component heated by the heated air; and
a controller in communication with the sensor to register the current infrared radiation image to at least one infrared reference image data, wherein the controller is operable to estimate a thermal transfer function at one or more pixels of the current infrared radiation image for comparison to a thermal transfer function at one or more pixels of the at least one reference image; comparing the thermal transfer function at one or more pixels of the infrared radiation image to a thermal transfer function at one or more pixels of at least one reference image; determining a difference between the thermal transfer function at one or more pixels of the current infrared radiation image to the thermal transfer function at one or more pixels of the at least one reference image; and classifying the component based on the comparing.
2. The system as recited in claim 1 , wherein the sensor comprises a thermography system.
3. The system as recited in claim 2 , wherein the thermography system comprises one or more of a short-wave infrared (SWIR) module, a mid-wave infrared (MWIR) module, a long-wave infrared (LWIR) module, a very long-wave infrared (VLWIR) module, and a broadband infrared module.
4. The system as recited in claim 3 , wherein the thermography system utilizes beam splitters to view the component through a single lens.
5. The system as recited in claim 1 , further comprising an image recognition algorithm to match a location of the component against a database that contains images of previously inspected components wherein the images of previously inspected components have associated previous transfer functions.
6. The system as recited in claim 5 , wherein the database comprises a multiple of reference images.
7. The system as recited in claim 5 , wherein the transfer function of a location of a component and a previous transfer function is utilized to determine acceptable and unacceptable components.
8. The system as recited in claim 7 , wherein the database is utilized to score a component being inspected.
9. A method for nondestructive coating inspection of a component, the method comprising:
communicating one or more of heated and cooled air into a component;
determining an infrared radiation image data of the component at least one of before, during, and after the heated air is communicated into the component;
estimating a thermal transfer function at one or more pixels of the current infrared radiation image, the thermal transfer function at one or more pixels of the at least one infrared reference image is a representation of an ideal component;
comparing the thermal transfer function at one or more pixels of the infrared radiation image data to a thermal transfer function at one or more pixels of at least one reference image;
determining a difference between the thermal transfer function at one or more pixels of the current infrared radiation image to the thermal transfer function at one or more pixels of the at least one reference image; and
classifying the component based on the comparing.
10. The method as recited in claim 9 , wherein classifying the component comprises identifying whether the component is acceptable or unacceptable.
11. The method as recited in claim 9 , wherein determining the difference between the thermal transfer functions comprises determining one or more of a sum of the absolute value of the coefficient-by-coefficient differences, a Bhattacharyya distance, a Kantorovich metric, a Kolmogorov-Smirnov statistic, and a Kullback-Leibler divergence.
12. The method as recited in claim 9 , further comprising determining a cause of the difference, a cause of the difference comprises determining at least one of a coating thickness, adhesion, or crack in a coating of the component.
13. The method as recited in claim 9 , wherein the difference determines whether the component is acceptable or unacceptable.
14. The method as recited in claim 9 , further comprising modeling an internal structure of a component at one or more pixels of the current infrared radiation image.