Abstract: Based on the classical Prony theory, a new time　varying multivariate Prony method is put forward, which can simultaneously treat with multidimensional nonstationary　signals. And the application of the proposed method to the modal parameter identification of time varying MDOF systems is investigated. The difficult problem of estimating the time varying parameter matrices of the time varying multivariate model is solved by using the modified recursive least square method. Satisfying results are obtained through the simulation of a time varying planar manipulator system. It is proved that the method presented has accurate computing and good tracking capacities in the modal identification of time varying structures.

Key words: Time varying multivariate Prony method Modal parameter　Vibration　Nonstationary