System and method for aligning two work pieces with a vision system in the presence of occlusion

A system for aligning a first work piece that is assembled to an underlying second work piece comprising:

• a vision system camera assembly configured to image a scene containing the first work piece and the second work piece;
• and
• an alignment process receiving image data with respect to the scene from the vision system camera assembly, the alignment process being constructed and arranged to,
• (a) identify secondary alignment features in the first work piece and the second work piece, the secondary alignment features remaining visible during the alignment process,
• (b) move at least one of a manipulator or a motion stage to move at least one of the first work piece or the second work piece in order to concurrently expose at least one occluded first primary alignment feature in at the least one of the first work piece or the second work piece, the at least one occluded first primary alignment feature comprising a first edge and a second edge,
• (c) acquire at least one first image of the scene, the at least one first image of the scene including the at least one exposed first primary alignment feature,
• (d) move at least one of the manipulator or the motion stage to move at least one of the first work piece and the second work piece to concurrently expose at least one occluded second primary alignment feature, the at least one occluded second primary alignment feature comprising a third edge opposing the first edge and a fourth edge opposing the second edge, and
• (e) acquire at least one second image of the scene, and based upon the at least one first image and the least one second image, establish a relationship between the primary alignment features and the secondary alignment features to enable alignment of the first work piece and the second work piece.