Real-time Modal Parameter Identification of a Variable-Topology Truss Structure via Transporting Robots
Yicheng Wang, Jialiang Sun, Hao Wen, Fushou Liu
Abstract: During on-orbit assembly, topology variations of space trusses lead to abrupt changes in modal characteristics, potentially inducing undesired dynamic responses under small disturbances. To provide a reliable and accurate dynamic model for subsequent control, it is necessary to perform accurate and real-time identification of the truss eigenfrequencies during the transportation phase. This paper proposes a modal identification framework for variable-topology space trusses based on the constraint forces measured at the transporting robot grasping nodes. Firstly, the Absolute Nodal Coordinate Formulation (ANCF) is employed to establish an accurate orbital dynamic model of a space truss structure and compute its corresponding eigenfrequencies and mode shapes. Secondly, the constraint forces are employed for modal identification using the Standardized Autoregressive (SAR) power spectral density function. The effects of different grasping strategies on modal identification results of variable-topology trusses are investigated. Finally, a ground experiment is conducted to identify the first eigenfrequency of a thin plate by using a grasping robot and compared with ANSYS to validate the proposed real-time modal identification method.
文章链接：https://www.sciencedirect.com/science/article/pii/S0273117726001535
