Combining feature boundaries

A method of inspecting a test part by forming a combined feature boundary representing a boundary of the test part based on first and second feature boundaries of overlapping portions of the test part, comprising:

• extracting the first and second feature boundaries from measurements of the overlapping portions of the test part taken by at least one measuring instrument;
• calculating parametric coordinates of a plurality of crossing points, wherein the plurality of crossing points are formed by intersections of the first and second feature boundaries;
• organizing the plurality of crossing points into a sorted order based on their respective parametric coordinates;
• determining a mathematical sign of a cross product formed by the intersections at each crossing point;
• defining a path of the combined feature boundary between each of the plurality of crossing points based on the mathematical sign, the combined feature boundary comprising each of the plurality of crossing points arranged according to the sorted order and a portion of at least one of the first and second feature boundaries;
• calculating an area defined by the combined feature boundary;
• determining a feature type associated with the combined feature boundary based on a mathematical sign of the calculated area;
• and
• presenting the combined feature boundary as the determined feature type for comparison with a predetermined standard for accepting or rejecting the test part.

A method of inspecting features of a test part by forming a combined feature list from first and second lists of features, comprising:

• obtaining first and second lists of features from at least one measuring instrument, wherein the first and second lists of features are acquired from measurements of overlapping portions of the test part;
• identifying a plurality of crossing points formed by boundaries of features in the first list overlapping with boundaries of features in the second list;
• calculating parametric coordinates of each identified crossing point;
• sorting each of the crossing points according to their respective parametric coordinates and forming a plurality of combined feature boundaries using the sorted crossing points;
• adding each of the combined feature boundaries to the combined feature list;
• and
• comparing the combined feature boundaries to a predetermined standard for accepting or rejecting the test part.

A method of inspecting a succession of test parts in a manufacturing queue by forming a combined feature boundary of each test part based on first and second overlapping feature boundaries of the test part, comprising:

• extracting the first and second feature boundaries from images of the overlapping portions of each test part;
• creating an ordered list of crossing points formed by the overlapping feature boundaries of each test part;
• forming a first portion of the combined feature boundary extending along the first feature boundary in a first direction and terminating at a first crossing point in the ordered crossing point list;
• selecting the second feature boundary;
• forming a second portion of the combined feature boundary connected to the first portion, the second portion extending along the second feature boundary in the first direction and terminating at a second crossing point of the ordered list;
• comparing coordinates of the combined feature boundaries to a predetermined standard for accepting or rejecting each of the test parts;
• and
• producing signals based on the comparison for advancing the accepted test parts for further processing or removing the rejected tests parts from the queue.