Experiment design for improved frequency domain subspace system identification of continuous-time systems
Artikel i vetenskaplig tidskrift, 2015

A widely used approach for identification of linear, time-invariant, MIMO (multi-input/multi output) systems from continuous-time frequency response data is to solve it in discrete-time domain using subspace based identification algorithm incorporated with a bilinear transformation. However, the bilinear transformation maps the distribution of the frequency lines from continuous-time domain to discrete-time domain in a non-linear fashion which may make identification algorithm to be ill-conditioned. In this paper we propose a solution to get around this problem by designing a dedicated frequency sampling strategy. Promising results are obtained when the algorithm is applied to synthetic data from a 6DOF mass-spring model.

Subspace methods

Frequency sampling strategy

Frequency responses

System identification

Bias reduction


Majid Khorsand Vakilzadeh

Chalmers, Tillämpad mekanik, Dynamik

Vahid Yaghoubi Nasrabadi

Chalmers, Tillämpad mekanik, Dynamik

Tomas McKelvey

Chalmers, Signaler och system, Signalbehandling och medicinsk teknik, Signalbehandling

Thomas Abrahamsson

Chalmers, Tillämpad mekanik, Dynamik

Lennart Ljung

Linkvping University


2405-8963 (ISSN)

Vol. 48 886-891