中文摘要：

考虑大型挠性部件运动导致的在轨航天器模态参数时变特性,提出一种改进的截断窗逼近幂迭代（TW-API）追踪方法。针对传统TW-API方法计算量较大的问题,改进的方法简化了数据处理中的矩阵递推过程,显著减少了在轨辨识过程的计算量和计算时间。还将该方法与经典投影估计子空间跟踪（PAST）方法和逼近幂迭代（API）递推方法进行了计算量对比与分析。为检验四种方法用于航天器模态参数辨识的效果,选取ETSVIII卫星为对象进行数值仿真。通过实际计算时间的比较,校验了改进TW-API方法在大型挠性航天器时变模态参数在轨辨识方面的有效性。

英文摘要：

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.