Estimation Method Of Position And Orientation Of Aircraft Components Based On Tolerance Constraints

The entire airplane is assembled by large components in aircraft assembly. To ensure the assembly accuracy, large components should be aligned to the target posture to meet the assembly requirements. This paper relies on the projects assumed by Zhejiang University, and mainly researches and explores the technologies of large components digital alignment by establishing the optimization model of aircraft components based on tolerance constraints which include manufacture accuracy and coordination accuracy. By solving this problem, the optimized postures of large components are obtained, which makes the manufacture accuracy and coordination accuracy be met and the synthesis assembly error minimal.In chapter1, the current research on aircraft digital assembly at home and abroad is introduced and the key technologies of large components digital alignment are summarized. The research background and goals are presented based on the detailed introduction of the current aircraft alignment. Finally, the overall framework of the paper is given. In chapter2, the basic concept of tolerance constraints which include manufacture accuracy and coordination accuracy in the process of aircraft digital alignment is introduced. As the large components can be seen as rigid bodies, the description of rigid body’s posture transformation in the3D space is given. With the relationships between different coordinate systems in the aircraft assembly, an evaluation method of error allocation with3D tolerance for feature points of large components is proposed. In chapter3, by analyzing two kinds of out of tolerance conditions of fuselage-wing joints and level-measuring points, an optimization algorithm of the single component digital alignment is proposed. Then the optimization model of the single component digital alignment based on manufacture accuracy of fuselage-wing joints and coordination accuracy of level-measuring points is built. Finally the optimized posture of the wing is obtained by solving the problem and the method is validated through simulated data. In chapter4, by analyzing two kinds of out of tolerance conditions of fuselage-fuselage joints and coordinate position between the fuselage-fuselage, an optimization algorithm of the multi-components digital alignment is proposed. Then the optimization model of the multi-components digital alignment based on manufacture accuracy of fuselage-fuselage joints and coordination accuracy of coordinate position between the fuselage-fuselage is built. Finally the optimized postures of the fuselages are obtained by solving the problem and the method is validated through simulated data. In chapter5, the module of large components digital alignment is developed according to the technological process. Then the methods of data integration and task integration in the system are introduced. The design and implementation of multi-components digital alignment is given and finally the main interfaces of the software are presented. In chapter6, summary for whole work in this paper is given and the future work is discussed.