关键词: 模态参数识别, 时变Prony法, 基函数, 线性时变系统

Abstract: Modal parameter identification of a time-variant linear vibration system by autoregressive modeling and Prony analysis is studied in this paper. Based on the classical Prony analysis, an improved method to process nonstationary signals is presented. The recursive least squares is adopted to estimate model parameters, and the choice of the basis functions are discussed. It shows that some basis functions such as time polynomial, discrete long spherical and discrete cosine are more suitable to modal parameter identification than other ones. To validate the proposed method, digital simulation and a test of a cantilever beam with an adjustable mass are completed. The comparison between identification results and theoretical results indicates that the proposed method is effective and feasible to identify modal parameters of time-variant linear system.

Key words: modal parameter identification, time varying Prony method, basis function, time-variant linear system.