Assessment of large-scale assembly coordination based on pose feasible space

The characteristics of large-scale products, such as large size, multi coordination features, and deformation, often lead to the difficulty of satisfying assembly requirements which reduces the assembly efficiency. In the domain of measurement-assisted assembly, assembly is realized by pose adjustment. Geometric constraints form a set of assembly poses which satisfy all constraints. The pose set shows whether the parts can be assembled and whether they are easy to assemble. In this paper, small displacement torsor (SDT) is used to express the coordinated pose variation, and the inequalities constructed by geometric constraints are formulated. The pose feasible space (PFS) is proposed as the assessment index of assembly coordination. The pose relations of different assembly features are considered to analyze multi-features constraints. Finally, a simulation analysis of the wing-fuselage joints assembly is carried out. A Monte Carlo method based on SDT is used to solve PFS. Besides, the best-fit method is taken to calculate the optimal pose and to analyze the geometric constraints. The result shows the PFS can reflect the degree of assembly coordination.