Study on the Reason for Difference of Data-Driven and Covariance-driven Stochastic Subspace Identification Method

Parameter identification is currently one of the main research topics in the area of structural health monitoring. Stochastic subspace identification method can effectively identify modal parameters of linear structure from structure of ambient vibration. According to difference on the way processing response data, stochastic subspace identification method is divided into data-driven and covariance-driven stochastic subspace identification method, which traditionally is thought to be consistent with each other theoretically and practically. But the fact is that data driven stochastic subspace identification method is different with the covariance driven subspace identification method due to different ways on numerical computation practically. So the study is carried out for the reason why they are different with each other. In the process of analysis, 5-DOF mass-spring-dashpot system is adopted.