Patent ID: 7791025
Filing Date: 2010-09-07
Classification: G01J,G01M,G06T

Abstract:
1. A method of inspecting a plurality of features extending from a cavity within a structure to an outer surface of the structure by analyzing saved thermal images of an area of the outer surface including the plurality of features, the thermal images having been captured and saved at different times in response to first, heating the area of the outer surface, and thereafter, providing a cooled gas into the cavity and to the plurality of features, the method comprising: (a) identifying a first thermal image captured after providing the cooled gas into the cavity, the first thermal image comprising an array of pixels of the area of the outer surface including the plurality of features, wherein each pixel represents a temperature; (b) determining a plurality of standard deviations of temperatures, each of the plurality of standard deviations being determined by temperatures represented by pixels within a boundary of a different one of the features; (c) determining an average of the plurality of standard deviations of temperatures; (d) determining a threshold temperature using the average of the plurality of standard deviations of temperatures; (e) determining a minimum temperature represented by pixels within boundaries of respective ones of the plurality of features; (f) identifying a number of significant pixels within the boundary of one of the features, each significant pixel representing a temperature less than a sum of the threshold temperature plus the minimum temperature, and the number of significant pixels representing an area of the one of the features allowing a desired flow of the cooled gas; (g) identifying the one of the features as a good feature in response to the number of significant pixels being greater than a predetermined number; and (h) iterating steps (f) through (g) for each of the plurality of features.