This paper proposes a new algorithm for the online monitoring of slow varying modal parameters in vibrating structures subjected to unknown excitations. In this method, an Auto-Regressive (AR) model will be applied in a Short-Time Sliding Window (STSW) on measured signals. The model parameters will be determined and updated through the order and time obtained from the previous computational window. The recursive multivariable least-squares method is utilized in conjunction with the Schur complement method to find solutions. Numerical simulations of the gradual changing system acted by the random excitations and sinusoidal force are presented. Finally, the modal parameters for the multichannel data measured on an experimental steel plate emerging from the water are identified and compared with those obtained with the analytical method and Short-Time Fourier Transform (STFT), providing a powerful means of validating the proposed method.

本文提出了一种新算法，用于在线监测未知激振条件下的振动结构中缓慢变化的模态参数。在这种方法中，将在短时滑动窗口（STSW）中对测量的信号应用自回归（AR）模型。将通过从先前的计算窗口获得的顺序和时间来确定和更新模型参数。递归多变量最小二乘方法与Schur补码方法结合使用以找到解决方案。给出了随机激励和正弦力作用下的渐进变化系统的数值模拟。最后，