Dynamic multi-constrained assembly sequence planning of large space structures considering structural vibration

Abstract

The assembly sequence planning problem of large space structure (LSS) is investigated in this paper, from the view of structural vibration. With the goal of reducing structural vibration and improving structural stability during assembly, the whole planning problem is decomposed into multiple problems of optimal assembly positions at each operation. Adopting the plate-type LSS and the truss-type LSS as specific objectives, a dynamic multi-constrained assembly sequence planning algorithm is then proposed based on structural dynamics modelling and modified genetic algorithm (GA). Selecting the structural frequencies to quantitatively describe structural stability of LSS, the algorithm is implemented through a designed procedure including an external loop and an internal loop. The dynamic assembly constraints, including geometric constraint, dynamics constraint, non-repeatability, realizability and continuity, are handled in the internal loop through assembly information delivered from the external loop. Numerical simulations of the two types of LSS are finally provided to testify the feasibility of the proposed sequence planning algorithm. The results show that the obtained sequences can effectively make LSS characterized by weak structural vibration during assembly.