Position and orientation best-fitting based on deterministic theory during large scale assembly

Position and orientation (p&o) of the large-size component are very important geometrical quantities, which are observed by digital metrology techniques and controlled by fixed or flexible fixtures during assembly. the observed p&o values are usually calculated using measured coordinates of several points on the surface of the large-size component, based on the precondition that the relative position of those points is unchanged. in this paper, a novel p&o best-fitting algorithm is proposed. the related work firstly discussed the influences of the structural deformation of the large-size component on the p&o observation during assembly, and then introduced a deterministic theory for considering the influences. based on the deterministic theory, the novel best-fitting algorithm which includes three steps was detailed. finally, based on a wing-fuselage alignment case, the proposed algorithm is verified to be more accurate than the traditional methods, and the computing process is verging and stable.