Abstract:

Considering the time-varying modal parameters of on-orbit spacecraft caused by the motion of large flexible appendages, an improved truncated window approximation power iteration (TW-API) tracking approach is proposed in this paper. Since the traditional TW-API has high computational complexity, the improved TW-API approach can significantly reduce the computational effort and computation time of on-orbit identification by simplifying the matrix recursion procedure during data processing. Meanwhile, the proposed approach is compared with classical projection approximation subspace tracking (PAST) and approximation power interation (API) recursive methods in computational effort. The ETS-VIII parameters are adopted in the simulation to verify the performance of the above mentioned approaches in spacecraft modal parameter identification. By the comparison of calculation time, the results demonstrate that the improved TW-API approach is effective in on-orbit identification of time-varying modal parameter of large flexible spacecraft.

Key words: Modal parameter identification, Large flexible spacecraft, On-orbit identification, Time-varying system