Two new fast identification algorithms of time-varying modal parameters based on subspace tracking

Abstract

The procedure of fast identification algorithms of the time-varying modal parameter based subspace tracking is investigated in this paper.After the pretreatment to the updating input/output data,the problem of fast time-varying modal parameter identification changes to be a subspace tracking problem principally.Adopting the principal subspace tracking algorithms,the fast time-varying modal parameter identification algorithms can be deduced.Replacing PAST by NPI and API,two new versions of time-varying modal parameter identification algorithms are proposed.The performance of the fast modal parameter identification algorithms based on different principal subspace tracking algorithms are compared by applying them on a classical time-varying mechanical system of a moving distributed mass-cantilever beam and a 2-DOF spring-mass model.