Patent ID: 7860601

Claim:
A method for characterizing the profile for each of a plurality of holes of a distorted processed workpiece following a processing step capable of distorting the workpiece, the method comprising: providing a first list of approximate hole locations derived from a CNC program used for producing the holes of the distorted processed workpiece prior to processing and defining a first scan path; relative to the processed workpiece, advancing a laser scanner head on a machine tool along the first scan path to determine two edge locations forming a first chord of a first hole; storing values for the edge locations of the first hole; determining a first chord length of the first hole; comparing the first chord length of the first hole to a predetermined minimum and maximum chord value range and in the event that the first chord length is outside the predetermined minimum and maximum chord value range, incrementally adjusting the scan path accordingly; relative to the processed workpiece, advancing a laser scanner head along the first scan path to determine two edge locations forming a first chord of a second hole in succession to the first hole; storing values for the edge locations of the second hole; determining a first chord length of the second hole; comparing the first chord length of the second hole to the predetermined minimum and maximum chord value range and in the event that the first chord length of the second hole is outside the predetermined minimum and maximum chord value ranges, incrementally adjusting the first scan path accordingly; relative to the processed workpiece, advancing the laser scanner head on the machine tool along the first scan path to determine two edge locations forming a first chord for each successive hole in the first scan path; storing values for the edge locations for each successive hole along the first scan path; determining a first chord length of each successive hole in the first scan path; relative to the processed workpiece, advancing the scanner head along a second scan path to determine two edge locations forming a second chord of each successive hole in the first list along the second scan path; storing values for the edge locations for each successive hole in the second scan path; and determining a second chord length of each successive hole in the first list in the second scan path; with the first and second chord lengths for each hole, characterizing a center for each hole in the first list.