Natural Frequency- and Surface Accuracy-Targeted Uncertain on-Orbit Assembly Sequence Planning for Large Space Structure With Topological Constraints and Vibration Reliability

On-orbit assembly is the main approach to constructing large space structure (LSS) in the future. To strictly meet the topological constraints and vibration reliability during the assembly process, this study proposes an uncertain on-orbit assembly sequence planning strategy for LSS aimed at improving both natural frequency and surface accuracy. On-orbit assembly dynamics of plate-like LSS is established based on the expandable modelling method with continuous updates, enabling both geometrically expanding and dynamically time-varying dynamic models and state-space representations. An efficient uncertainty propagation method is applied to estimate the response of the assembly process with only limited uncertain data. As long as the uncertainty bounds of the LSS in the assembly process are known, the displacement interval of the plate-like structure can be accurately and quickly predicted. Two important constraints, namely assembly topological constraint and vibration reliability, are established based on the assembly geometric topology configuration of LSS modules and the time-dependent reliability analysis of vibration response under a given threshold. Combining the above two constraints, an uncertain on-orbit assembly sequence planning for LSS based on a “ring” approach is proposed with dual targets of natural frequency and surface accuracy, which is solved using an advanced multi-objective optimization approach. Finally, an assembly planning example of a multi-modular plate-like LSS is utilized to verify the accuracy of this study.