Methods and apparatus for automated part positioning based on geometrical comparisons

Abstract

A method of determining a rigid motion between a master solid model and an approximated target model (or, more generally, between any two models having different types) includes identifying, within each model, geometrical entities having a unique characteristic, and then determining the best match between the identified geometric entities. The system provides, in machine-readable form, a master model comprising a precise definition of a three-dimensional solid and a target model comprising a simplified definition of the three-dimensional solid. Then it identifies a first set of geometric entities (e.g., planar faces) within the master model that have a unique characteristic (e.g., planar area), and identifies a second set of geometric entities in the target model that have the unique characteristic. The system then determines a best match between a member of the first set of geometric entities and a member of the second set of geometric entities using, for example, a Hungarian matching algorithm. Linear edges of matched faces are compared to determine the appropriate rigid motion.