A combined hole position error correction method for automated drilling of large-span aerospace assembly structures

Abstract

PurposeAerospace assembly demands high drilling position accuracy for fastener holes. Hole position error correction is a key issue to meet the required hole position accuracy. This paper aims to propose a combined hole position error correction method to achieve high positioning accuracy.Design/methodology/approachThe bilinear interpolation surface function based on the shape of the aerospace structure is capable of dealing with position error of non-gravity deformation. A gravity deformation model is developed based on mechanics theory to efficiently correct deformation error caused by gravity. Moreover, three solution strategies of the average, least-squares and genetic optimization algorithms are used to solve the coefficients in the gravity deformation model to further improve position accuracy and efficiency.FindingsExperimental validation shows that the combined position error correction method proposed in this paper significantly reduces the position errors of fastener holes from 1.106 to 0.123 mm. The total position error is reduced by 43.49% compared with the traditional mechanics theory method.Research limitations/implicationsThe position error correlation method could reach an accuracy of millimeter or submillimeter scale, which may not satisfy higher precision.Practical implicationsThe proposed position error correction method has been integrated into the automatic drilling machine to ensure the drilling position accuracy.Social implicationsThe proposed position error method could promote the wide application of automatic drilling and riveting machining system in aerospace industry.Originality/valueA combined position error correction method and the complete roadmap for error compensation are proposed. The position accuracy of fastener holes is reduced stably below 0.2 mm, which can fulfill the requirements of aero-structural assembly.