系统识别过程中参数协差阵的先验估计

THE PRIOR ESTIMATION FOR COVARIANCE MATRIX OF STRUCTURAL PARAMETERS IN SYSTEM IDENTIFICATION PROCEDURES

系统识别的损伤检测和估计是建立在参数估计上的。当考虑参数的随机特性时，必须对参数的方差和参数之间的相关系数作出估计。本文提出了参数协差阵的先验估计方法，对于同一单元内不同类型的参数，通过将参数分解为一系列统计独立的要素，利用函数协差阵与变量协差阵之间的关系求得参数的协差阵。不同单元的同一类型参数的相关系数通过对检测数据的数理统计或利用工程师的经验得到估计。

The damage detection and assessment algorithm of system identification are based on a parameter estimation. As the random properties of parameters are considered, it is necessary to estimate the variation of parameters and correlation coefficient between parameters. A rational method for prior estimation for covariance matrix of parameters is presented in this paper. For different parameters in an element, the covariance matrix of parameters can be obtained by dividing parameters into a series of statistical independent factors and using the covariance matrix relationship between function and variable. The correlation coefficient of parameters of same type in different elements is estimated by test data or empiric formula.