利用输出误差时间序列模型识别结构时变模态参数

摘要

An output-error(OE) time series model, which describes input and output relationship of the system, is established based on the motion equation of the vibration system. The property of exogeneous polynomial coefficients for the OE model is discussed. The parameter estimation algorithm referred to recursive least square method, which is based on UD decomposition, is used to estimate parameters for the OE model. Time-varying modal parameters of the structure are obtained. Simulation results show that this approach is feasible for identifying time-varying modal parameters.%基于振动系统运动方程，建立了描述系统输入和输出关系的输出误差时间序列模型，论证了该模型中外源多项式系数的性质。利用基于UD分解的递归最小二乘参数估计方法估计OE模型的参数，从而得到结构的时变模态参数。数值仿真结果表明用此方法来识别时变模态参数是可行的。