关键词: 子空间, 加权, 噪声, 参数辨识

Abstract:

In order to reduce the noise effect in frequency-domain subspace algorithm for mode identification,a new weighted frequency subspace algorithm was put forward herein.The noise variance in frequency domain was estimated with a few experiments.The weight matrix was made up of the weight coefficient from the estimated variance of the input and output.This algorithm considered the noise of the input and output and allocated the weight with variance in frequency domain.The simulation was carried out on a system with two DOF  to validate the effect.The experiments on a variable section were put up.The results from the simulation and experiments show that the improved algorithm can exactly get the modal parameters under the conditions with  strong noise.

Key words: subspace, weight, noise, parameter identification