System and method for joining workpieces to form an article

A method for forming a multi-piece assembly by joining mating workpieces in a workstation, the workstation having a frame with at least one fixed locator and at least one adjustable locator, wherein each workpiece has at least one physical feature, the position of which within the multi-piece assembly is expressed in a collection of assembly data, the method having a processor coupled to the workstation and one or more hardware-based fixtures that are mechanically operated and/or electronically controlled by the processor, comprising:

• placing, by a positioning fixture, the workpieces in the workstation so that one of said workpieces is in registration with the fixed locator;
• obtaining, at the processor, measurement data reflecting the positions of the respective features of the workpieces and representing the measurement data in a common reference frame associated with the fixed locator;
• receiving and storing, by the processor, the collection of assembly data and the measurement data;
• defining, by the processor, ordered pairs of mating features;
• using the processor to define and store in memory, for each ordered pair of mating features, a test vector that connects a pair of mating features, where each test vector has vector components represented as variables stored in memory;
• using the processor to computationally discover a best fit for the mating workpieces by collectively applying to the test vectors a computational optimization process that seeks to minimize the lengths of the test vectors while taking into account predefined weighting factors that give certain features locational preference over others;
• using the processor to reorient the data representing the feature locations of the respective workpieces in the common reference frameusing the computationally discovered best fit;
• using the processor to calculate the position in the common reference frame of a feature demarked for registration with the adjustable locator;
• moving the adjustable locator in relation to the frame to the calculated position of the feature demarked for registration with the adjustable locator and thereby establishing a best fit orientation of the mating workpieces in physical space, where the adjustable locator is moved by at least one of a motor or a robot controlled by the processor;
• positioning said mating workpieces in said best fit orientation by registration with said fixed and adjustable locators and then mechanically joining the mating workpieces.